Add desktop app service and VM dev session tooling

Introduces a new `core/applications` QML/C++ module (`Nebula.Applications`) to discover `.desktop` entries, expose filterable application models, and launch installed apps safely from the shell. The desktop launcher now uses real installed apps with themed icon loading and fallback glyphs, adds output-aware surface sizing via `OutputTracker`, and wires in image/icon providers. It also adds VMware-focused Sway/shell wrapper scripts, updates Sway config/session env defaults, and refreshes README docs to document the new development flow and Desktop 0.1 behavior.

README.md

@@ -6,7 +6,8 @@ A Linux desktop environment built around a custom compositor, shell, and service
 
 | Path | Purpose |
 |------|---------|
-| `core/nebula-core` | Core runtime and platform APIs |
+| `core/nebula-core` | Core runtime and platform APIs (growing) |
+| `core/applications` | Installed `.desktop` discovery and launching |
 | `compositor/` | Compositor configuration (Sway is temporary) |
 | `shells/` | Desktop and future Bigscreen shells |
 | `packages/` | Shared UI (`Nebula.UI`), icons, API, and design tokens |
@@ -14,12 +15,13 @@ A Linux desktop environment built around a custom compositor, shell, and service
 | `session/` | Session manager and desktop entry |
 | `packaging/` | Distribution packaging (Ubuntu) |
 | `branding/` | Boot assets, wallpapers, and sounds |
+| `scripts/` | Development helpers (including the VMware shell wrapper) |
 
 ## Shells
 
-**Nebula Desktop** (production) is a C++20 Qt Quick/QML Wayland shell using LayerShellQt. See `shells/desktop/`.
+**Nebula Desktop 0.1** is a C++20 Qt Quick/QML Wayland shell using LayerShellQt. It can discover installed applications and launch them (including Foot) from the GUI. See `shells/desktop/`.
 
-**Nebula Bigscreen** is planned as a separate Qt Quick/QML shell with a controller-first interaction model, sharing `Nebula.UI` and Nebula Core.
+**Nebula Bigscreen** is planned as a separate Qt Quick/QML shell with a controller-first interaction model, sharing `Nebula.UI` and `Nebula.Applications`.
 
 Standalone Nebula applications may still use React/Tauri where that is a better fit. The operating-system shell does not.
 
@@ -39,8 +41,27 @@ Nebula Shell  Qt Quick/QML
 
 Applications and games render on their own Wayland/XWayland paths. They are not composited inside QML.
 
-## Getting started
+## Getting started (development VM)
 
-Desktop shell build instructions: `shells/desktop/README.md`.
+```bash
+cd shells/desktop/shell
+rm -rf build
+cmake -S . -B build
+cmake --build build -j$(nproc)
+```
+
+Then, from the repository root:
+
+```bash
+./compositor/sway/dev/run-sway-vm.sh
+```
+
+or:
+
+```bash
+sway -c compositor/sway/nebula-sway.conf
+```
+
+The VMware wrapper sets `QT_QUICK_BACKEND=software`. Production `nebula-shell` does not. Details: `shells/desktop/README.md` and `compositor/README.md`.
 
 The Qt shell must be compiled on Linux (the Ubuntu NebulaOS VM). It will not build on Windows.

compositor/README.md

@@ -7,7 +7,7 @@ Sway currently provides:
 - Wayland compositor
 - application window management
 - XWayland
-- input
+- input and the pointer cursor
 - output handling
 
 Nebula provides the visible shell (Qt Quick/QML via LayerShellQt). The Sway config must not enable a Sway bar.
@@ -25,3 +25,61 @@ Nebula compositor    later
 Nebula Shell
 Qt Quick/QML
 ```
+
+## Development session
+
+From the NebulaOS repository root:
+
+```bash
+sway -c compositor/sway/nebula-sway.conf
+```
+
+Recommended on the Ubuntu VMware VM (repo-root `cd`, cursor environment, software cursors):
+
+```bash
+./compositor/sway/dev/run-sway-vm.sh
+```
+
+Sway then autostarts Nebula Desktop through `scripts/run-nebula-vm.sh`.
+
+Skip shell autostart:
+
+```bash
+NEBULA_SHELL_AUTOSTART=0 ./compositor/sway/dev/run-sway-vm.sh
+```
+
+### Output / resolution
+
+The development config uses scale `1` and requests `1920x1080` when that mode is advertised. If it is not, Sway keeps the preferred mode. This is a VM convenience, not a production requirement.
+
+```bash
+swaymsg -t get_outputs
+swaymsg output <name> mode 1920x1080
+swaymsg output <name> scale 1
+```
+
+### Cursor
+
+```text
+seat * xcursor_theme Adwaita 24
+XCURSOR_THEME=Adwaita
+XCURSOR_SIZE=24
+```
+
+Requires `adwaita-icon-theme`. A Nebula-branded cursor theme is a later task.
+
+`WLR_NO_HARDWARE_CURSORS=1` is VMware-specific and is set by `run-sway-vm.sh`, not by production session files.
+
+### Emergency shortcuts
+
+| Shortcut | Action |
+|----------|--------|
+| Super+Enter | open Foot |
+| Super+Shift+E | exit Sway |
+| Super+Shift+C | reload Sway config |
+
+Normal application launching is done from the Nebula launcher, not these shortcuts.
+
+### Rendering
+
+`scripts/run-nebula-vm.sh` sets `QT_QUICK_BACKEND=software` for the VMware guest GPU. Production `nebula-shell` must not set that variable.

compositor/sway/dev/run-nebula-vm.sh

@@ -0,0 +1,5 @@
+#!/bin/sh
+# Convenience wrapper; the canonical VMware nebula-shell launcher is
+# scripts/run-nebula-vm.sh
+script_dir=$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)
+exec /bin/sh "${script_dir}/../../../scripts/run-nebula-vm.sh" "$@"

compositor/sway/dev/run-sway-vm.sh

@@ -0,0 +1,39 @@
+#!/bin/sh
+# Recommended VMware development session entry point.
+#
+# Sets compositor-side development environment (cursor theme, software
+# cursors if needed) and starts Sway with the Nebula development config.
+# Sway then autostarts nebula-shell via scripts/run-nebula-vm.sh.
+#
+# Usage:
+#   ./compositor/sway/dev/run-sway-vm.sh
+#
+# Equivalent:
+#   export XCURSOR_THEME=Adwaita XCURSOR_SIZE=24
+#   sway -c compositor/sway/nebula-sway.conf
+#
+# Skip shell autostart:
+#   NEBULA_SHELL_AUTOSTART=0 ./compositor/sway/dev/run-sway-vm.sh
+
+set -eu
+
+script_dir=$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)
+repo_root=$(CDPATH= cd -- "${script_dir}/../../.." && pwd)
+config="${repo_root}/compositor/sway/nebula-sway.conf"
+
+export XDG_CURRENT_DESKTOP="${XDG_CURRENT_DESKTOP:-NebulaOS}"
+export XDG_SESSION_DESKTOP="${XDG_SESSION_DESKTOP:-nebula}"
+export XCURSOR_THEME="${XCURSOR_THEME:-Adwaita}"
+export XCURSOR_SIZE="${XCURSOR_SIZE:-24}"
+
+# VMware often needs software cursors. This is development-specific.
+export WLR_NO_HARDWARE_CURSORS="${WLR_NO_HARDWARE_CURSORS:-1}"
+
+if [ ! -f "${config}" ]; then
+    echo "nebula: missing Sway config at ${config}" >&2
+    exit 1
+fi
+
+cd "${repo_root}"
+echo "nebula: starting Sway with ${config}"
+exec sway -c "${config}" "$@"

compositor/sway/nebula-sway.conf

@@ -2,17 +2,53 @@ set $mod Mod4
 set $term foot
 
 # NebulaOS temporary development compositor configuration
+#
+# Sway is invisible infrastructure. Nebula Desktop is the visible shell.
+# Do NOT add a bar block; Nebula provides its own top bar.
 
-# No Sway wallpaper or UI
+# -----------------------------------------------------------------------------
+# Output / resolution
+# -----------------------------------------------------------------------------
+# Development default: 1:1 scale, fill the current VMware display.
+# Request 1920x1080 when the output advertises that mode. If the mode is not
+# available, Sway keeps the output's preferred mode instead of failing.
+#
+# This is a development convenience, not a production architecture requirement.
+# Inspect modes:  swaymsg -t get_outputs
+# Force another mode (example):  swaymsg output <name> mode 1600x900
+output * scale 1
+output * mode 1920x1080
 output * bg #000000 solid_color
 
-# Development terminal
+# -----------------------------------------------------------------------------
+# Cursor
+# -----------------------------------------------------------------------------
+# The compositor owns the pointer cursor, not QML.
+# A branded Nebula cursor theme is a later task.
+seat * xcursor_theme Adwaita 24
+# If the cursor is invisible in VMware, start Sway with:
+#   WLR_NO_HARDWARE_CURSORS=1 sway -c compositor/sway/nebula-sway.conf
+# compositor/sway/dev/run-sway-vm.sh sets that automatically.
+
+# -----------------------------------------------------------------------------
+# Nebula shell autostart
+# -----------------------------------------------------------------------------
+# Starts nebula-shell through the VMware development wrapper, which sets
+# QT_QUICK_BACKEND=software. Production sessions must start nebula-shell
+# without that variable.
+#
+# Disable autostart for debugging:
+#   NEBULA_SHELL_AUTOSTART=0 sway -c compositor/sway/nebula-sway.conf
+#
+# Run from the repository root so this relative path resolves, or use
+# compositor/sway/dev/run-sway-vm.sh which does that for you.
+exec /bin/sh scripts/run-nebula-vm.sh
+
+# -----------------------------------------------------------------------------
+# Emergency development shortcuts (not the normal UX)
+# -----------------------------------------------------------------------------
 bindsym $mod+Return exec $term
-
-# Exit compositor
 bindsym $mod+Shift+e exec swaymsg exit
-
-# Reload configuration
 bindsym $mod+Shift+c reload
 
 # Remove Sway window decorations
@@ -21,6 +57,3 @@ default_floating_border pixel 0
 
 # Basic floating controls for development
 floating_modifier $mod normal
-
-# Do NOT add a bar block.
-# Nebula provides its own top bar.

core/applications/ApplicationFilterModel.cpp

@@ -0,0 +1,64 @@
+#include "ApplicationFilterModel.hpp"
+#include "ApplicationModel.hpp"
+
+ApplicationFilterModel::ApplicationFilterModel(QObject *parent)
+    : QSortFilterProxyModel(parent)
+{
+    setDynamicSortFilter(true);
+    setFilterCaseSensitivity(Qt::CaseInsensitive);
+
+    connect(this, &QAbstractItemModel::modelReset, this, &ApplicationFilterModel::countChanged);
+    connect(this, &QAbstractItemModel::rowsInserted, this, &ApplicationFilterModel::countChanged);
+    connect(this, &QAbstractItemModel::rowsRemoved, this, &ApplicationFilterModel::countChanged);
+    connect(this, &QAbstractItemModel::layoutChanged, this, &ApplicationFilterModel::countChanged);
+}
+
+QString ApplicationFilterModel::filter() const
+{
+    return m_filter;
+}
+
+void ApplicationFilterModel::setFilter(const QString &filter)
+{
+    const QString trimmed = filter.trimmed();
+    if (m_filter == trimmed)
+        return;
+
+    m_filter = trimmed;
+    invalidateFilter();
+    emit filterChanged();
+    emit countChanged();
+}
+
+int ApplicationFilterModel::count() const
+{
+    return rowCount();
+}
+
+bool ApplicationFilterModel::filterAcceptsRow(int sourceRow, const QModelIndex &sourceParent) const
+{
+    if (m_filter.isEmpty())
+        return true;
+
+    const QModelIndex index = sourceModel()->index(sourceRow, 0, sourceParent);
+    if (!index.isValid())
+        return false;
+
+    const auto matches = [this, &index](int role) {
+        return index.data(role).toString().contains(m_filter, Qt::CaseInsensitive);
+    };
+
+    if (matches(ApplicationModel::NameRole)
+        || matches(ApplicationModel::GenericNameRole)
+        || matches(ApplicationModel::CommentRole)) {
+        return true;
+    }
+
+    const QStringList categories = index.data(ApplicationModel::CategoriesRole).toStringList();
+    for (const QString &category : categories) {
+        if (category.contains(m_filter, Qt::CaseInsensitive))
+            return true;
+    }
+
+    return false;
+}

core/applications/ApplicationFilterModel.hpp

@@ -0,0 +1,30 @@
+#pragma once
+
+#include <QSortFilterProxyModel>
+#include <QtQml/qqmlregistration.h>
+
+class ApplicationFilterModel : public QSortFilterProxyModel
+{
+    Q_OBJECT
+    QML_ELEMENT
+    QML_UNCREATABLE("Obtained from ApplicationService")
+    Q_PROPERTY(QString filter READ filter WRITE setFilter NOTIFY filterChanged)
+    Q_PROPERTY(int count READ count NOTIFY countChanged)
+
+public:
+    explicit ApplicationFilterModel(QObject *parent = nullptr);
+
+    QString filter() const;
+    void setFilter(const QString &filter);
+    int count() const;
+
+signals:
+    void filterChanged();
+    void countChanged();
+
+protected:
+    bool filterAcceptsRow(int sourceRow, const QModelIndex &sourceParent) const override;
+
+private:
+    QString m_filter;
+};

core/applications/ApplicationModel.cpp

@@ -0,0 +1,93 @@
+#include "ApplicationModel.hpp"
+
+#include <algorithm>
+#include <utility>
+
+ApplicationModel::ApplicationModel(QObject *parent)
+    : QAbstractListModel(parent)
+{
+}
+
+int ApplicationModel::rowCount(const QModelIndex &parent) const
+{
+    if (parent.isValid())
+        return 0;
+    return m_entries.size();
+}
+
+int ApplicationModel::count() const
+{
+    return m_entries.size();
+}
+
+QVariant ApplicationModel::data(const QModelIndex &index, int role) const
+{
+    if (!index.isValid() || index.row() < 0 || index.row() >= m_entries.size())
+        return {};
+
+    const DesktopEntry &entry = m_entries.at(index.row());
+    switch (role) {
+    case DesktopIdRole:
+    case Qt::UserRole:
+        return entry.desktopId;
+    case NameRole:
+    case Qt::DisplayRole:
+        return entry.name;
+    case GenericNameRole:
+        return entry.genericName;
+    case CommentRole:
+        return entry.comment;
+    case IconNameRole:
+        return entry.icon;
+    case CategoriesRole:
+        return entry.categories;
+    case TerminalRole:
+        return entry.terminal;
+    default:
+        return {};
+    }
+}
+
+QHash<int, QByteArray> ApplicationModel::roleNames() const
+{
+    return {
+        {DesktopIdRole, QByteArrayLiteral("desktopId")},
+        {NameRole, QByteArrayLiteral("name")},
+        {GenericNameRole, QByteArrayLiteral("genericName")},
+        {CommentRole, QByteArrayLiteral("comment")},
+        {IconNameRole, QByteArrayLiteral("iconName")},
+        {CategoriesRole, QByteArrayLiteral("categories")},
+        {TerminalRole, QByteArrayLiteral("terminal")},
+    };
+}
+
+void ApplicationModel::setEntries(QVector<DesktopEntry> entries)
+{
+    std::sort(entries.begin(), entries.end(), [](const DesktopEntry &left, const DesktopEntry &right) {
+        const int order = QString::localeAwareCompare(left.name, right.name);
+        if (order != 0)
+            return order < 0;
+        return left.desktopId < right.desktopId;
+    });
+
+    beginResetModel();
+    m_entries = std::move(entries);
+    endResetModel();
+    emit countChanged();
+}
+
+const DesktopEntry *ApplicationModel::entryAt(int row) const
+{
+    if (row < 0 || row >= m_entries.size())
+        return nullptr;
+    return &m_entries.at(row);
+}
+
+const DesktopEntry *ApplicationModel::entryById(const QString &desktopId) const
+{
+    for (const DesktopEntry &entry : m_entries) {
+        if (entry.desktopId == desktopId)
+            return &entry;
+    }
+    return nullptr;
+}

core/applications/ApplicationModel.hpp

@@ -0,0 +1,44 @@
+#pragma once
+
+#include "DesktopEntry.hpp"
+
+#include <QAbstractListModel>
+#include <QVector>
+#include <QtQml/qqmlregistration.h>
+
+class ApplicationModel : public QAbstractListModel
+{
+    Q_OBJECT
+    QML_ELEMENT
+    QML_UNCREATABLE("Obtained from ApplicationService")
+    Q_PROPERTY(int count READ count NOTIFY countChanged)
+
+public:
+    enum Roles {
+        DesktopIdRole = Qt::UserRole + 1,
+        NameRole,
+        GenericNameRole,
+        CommentRole,
+        IconNameRole,
+        CategoriesRole,
+        TerminalRole
+    };
+    Q_ENUM(Roles)
+
+    explicit ApplicationModel(QObject *parent = nullptr);
+
+    int rowCount(const QModelIndex &parent = QModelIndex()) const override;
+    QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const override;
+    QHash<int, QByteArray> roleNames() const override;
+
+    int count() const;
+    void setEntries(QVector<DesktopEntry> entries);
+    const DesktopEntry *entryAt(int row) const;
+    const DesktopEntry *entryById(const QString &desktopId) const;
+
+signals:
+    void countChanged();
+
+private:
+    QVector<DesktopEntry> m_entries;
+};

core/applications/ApplicationService.cpp

@@ -0,0 +1,109 @@
+#include "ApplicationService.hpp"
+
+#include "DesktopEntry.hpp"
+
+#include <QDir>
+#include <QDirIterator>
+#include <QFileInfo>
+#include <QSet>
+#include <QVector>
+#include <utility>
+
+ApplicationService::ApplicationService(QObject *parent)
+    : QObject(parent)
+    , m_model(new ApplicationModel(this))
+    , m_filtered(new ApplicationFilterModel(this))
+{
+    m_filtered->setSourceModel(m_model);
+    m_filtered->setSortRole(ApplicationModel::NameRole);
+    m_filtered->sort(0, Qt::AscendingOrder);
+
+    connect(m_model, &ApplicationModel::countChanged, this, &ApplicationService::countChanged);
+    connect(m_filtered, &ApplicationFilterModel::filterChanged, this, &ApplicationService::filterChanged);
+
+    refresh();
+}
+
+ApplicationService *ApplicationService::create(QQmlEngine *engine, QJSEngine *)
+{
+    auto *service = new ApplicationService(engine);
+    QQmlEngine::setObjectOwnership(service, QQmlEngine::CppOwnership);
+    return service;
+}
+
+ApplicationModel *ApplicationService::model() const
+{
+    return m_model;
+}
+
+ApplicationFilterModel *ApplicationService::filteredModel() const
+{
+    return m_filtered;
+}
+
+QString ApplicationService::filter() const
+{
+    return m_filtered->filter();
+}
+
+void ApplicationService::setFilter(const QString &filter)
+{
+    m_filtered->setFilter(filter);
+}
+
+int ApplicationService::count() const
+{
+    return m_model->count();
+}
+
+bool ApplicationService::launch(const QString &desktopId) const
+{
+    const DesktopEntry *entry = m_model->entryById(desktopId);
+    if (!entry) {
+        qWarning("nebula: unknown application %s", qPrintable(desktopId));
+        return false;
+    }
+    return entry->launch();
+}
+
+void ApplicationService::refresh()
+{
+    QVector<DesktopEntry> entries;
+    QSet<QString> seenIds;
+
+    const QStringList directories = applicationDirectories();
+    qInfo("nebula: scanning %d application director%s",
+          directories.size(),
+          directories.size() == 1 ? "y" : "ies");
+
+    for (const QString &directory : directories) {
+        QDir dir(directory);
+        if (!dir.exists())
+            continue;
+
+        QDirIterator iterator(directory, {QStringLiteral("*.desktop")}, QDir::Files, QDirIterator::Subdirectories);
+        while (iterator.hasNext()) {
+            const QString filePath = iterator.next();
+            QString relative = QDir(directory).relativeFilePath(filePath);
+            relative.replace(QLatin1Char('/'), QLatin1Char('-'));
+            const QString desktopId = relative;
+
+            if (seenIds.contains(desktopId))
+                continue;
+
+            seenIds.insert(desktopId);
+            DesktopEntry entry = parseDesktopEntryFile(filePath, desktopId);
+            if (entry.name.isEmpty())
+                entry.name = QFileInfo(filePath).completeBaseName();
+            if (!entry.isLauncherVisible())
+                continue;
+
+            entries.append(std::move(entry));
+        }
+    }
+
+    qInfo("nebula: discovered %d launcher application%s",
+          entries.size(),
+          entries.size() == 1 ? "" : "s");
+    m_model->setEntries(std::move(entries));
+}

core/applications/ApplicationService.hpp

@@ -0,0 +1,42 @@
+#pragma once
+
+#include "ApplicationFilterModel.hpp"
+#include "ApplicationModel.hpp"
+
+#include <QJSEngine>
+#include <QObject>
+#include <QQmlEngine>
+#include <QtQml/qqmlregistration.h>
+
+class ApplicationService : public QObject
+{
+    Q_OBJECT
+    QML_ELEMENT
+    QML_SINGLETON
+    Q_PROPERTY(ApplicationModel *model READ model CONSTANT)
+    Q_PROPERTY(ApplicationFilterModel *filteredModel READ filteredModel CONSTANT)
+    Q_PROPERTY(QString filter READ filter WRITE setFilter NOTIFY filterChanged)
+    Q_PROPERTY(int count READ count NOTIFY countChanged)
+
+public:
+    explicit ApplicationService(QObject *parent = nullptr);
+    static ApplicationService *create(QQmlEngine *engine, QJSEngine *scriptEngine);
+
+    ApplicationModel *model() const;
+    ApplicationFilterModel *filteredModel() const;
+
+    QString filter() const;
+    void setFilter(const QString &filter);
+    int count() const;
+
+    Q_INVOKABLE bool launch(const QString &desktopId) const;
+    Q_INVOKABLE void refresh();
+
+signals:
+    void filterChanged();
+    void countChanged();
+
+private:
+    ApplicationModel *m_model = nullptr;
+    ApplicationFilterModel *m_filtered = nullptr;
+};

core/applications/CMakeLists.txt

@@ -0,0 +1,44 @@
+cmake_minimum_required(VERSION 3.20)
+
+if(NOT TARGET Qt6::Qml)
+    project(NebulaApplications LANGUAGES CXX)
+    find_package(Qt6 6.4 REQUIRED COMPONENTS Core Gui Qml)
+    qt_standard_project_setup(REQUIRES 6.4)
+endif()
+
+qt_add_library(NebulaApplications STATIC)
+
+qt_add_qml_module(NebulaApplications
+    URI Nebula.Applications
+    VERSION 1.0
+    RESOURCE_PREFIX /qt/qml
+    SOURCES
+        DesktopEntry.hpp
+        DesktopEntry.cpp
+        ApplicationModel.hpp
+        ApplicationModel.cpp
+        ApplicationFilterModel.hpp
+        ApplicationFilterModel.cpp
+        ApplicationService.hpp
+        ApplicationService.cpp
+)
+
+target_include_directories(NebulaApplications
+    PUBLIC
+        "${CMAKE_CURRENT_SOURCE_DIR}"
+)
+
+target_link_libraries(NebulaApplications
+    PUBLIC
+        Qt6::Core
+        Qt6::Gui
+        Qt6::Qml
+)
+
+set_target_properties(NebulaApplications PROPERTIES
+    AUTOMOC ON
+)
+
+if(CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang")
+    target_compile_options(NebulaApplications PRIVATE -Wall -Wextra)
+endif()

core/applications/DesktopEntry.cpp

@@ -0,0 +1,413 @@
+#include "DesktopEntry.hpp"
+
+#include <QDir>
+#include <QFile>
+#include <QFileInfo>
+#include <QLocale>
+#include <QMap>
+#include <QProcess>
+#include <QStandardPaths>
+#include <QtGlobal>
+
+#include <utility>
+
+namespace {
+
+QString unquote(QString value)
+{
+    value = value.trimmed();
+    if (value.size() >= 2) {
+        const QChar first = value.front();
+        const QChar last = value.back();
+        if ((first == QLatin1Char('"') && last == QLatin1Char('"'))
+            || (first == QLatin1Char('\'') && last == QLatin1Char('\''))) {
+            value = value.mid(1, value.size() - 2);
+        }
+    }
+    return value;
+}
+
+bool parseBool(const QString &value)
+{
+    const QString lowered = value.trimmed().toLower();
+    return lowered == QLatin1String("true") || lowered == QLatin1String("1");
+}
+
+struct LocalizedValue
+{
+    QString fallback;
+    QMap<QString, QString> locales;
+};
+
+void storeLocalized(LocalizedValue *target, const QString &key, const QString &prefix, const QString &value)
+{
+    if (key == prefix) {
+        target->fallback = value;
+        return;
+    }
+
+    const QString start = prefix + QLatin1Char('[');
+    if (!key.startsWith(start) || !key.endsWith(QLatin1Char(']')))
+        return;
+
+    const QString locale = key.mid(start.size(), key.size() - start.size() - 1);
+    if (!locale.isEmpty())
+        target->locales.insert(locale, value);
+}
+
+QString resolveLocalized(const LocalizedValue &value, const QLocale &locale)
+{
+    const QString name = locale.name(); // e.g. en_US
+    const QString language = name.section(QLatin1Char('_'), 0, 0);
+
+    auto match = [&value](const QString &tag) -> QString {
+        if (tag.isEmpty())
+            return {};
+        return value.locales.value(tag);
+    };
+
+    if (QString found = match(name); !found.isEmpty())
+        return found;
+
+    if (QString found = match(language); !found.isEmpty())
+        return found;
+
+    const int underscore = name.indexOf(QLatin1Char('_'));
+    if (underscore > 0) {
+        if (QString found = match(name.left(underscore)); !found.isEmpty())
+            return found;
+    }
+
+    return value.fallback;
+}
+
+QString findTerminalEmulator()
+{
+    const QStringList candidates = {
+        QStringLiteral("foot"),
+        QStringLiteral("x-terminal-emulator"),
+        QStringLiteral("kitty"),
+        QStringLiteral("alacritty"),
+        QStringLiteral("kgx"),
+        QStringLiteral("gnome-terminal"),
+        QStringLiteral("konsole"),
+        QStringLiteral("xterm"),
+    };
+
+    for (const QString &name : candidates) {
+        const QString path = QStandardPaths::findExecutable(name);
+        if (!path.isEmpty())
+            return path;
+    }
+
+    return {};
+}
+
+bool executableAvailable(const QString &command)
+{
+    if (command.isEmpty())
+        return false;
+
+    const QFileInfo info(command);
+    if (info.isAbsolute())
+        return info.isExecutable();
+
+    return !QStandardPaths::findExecutable(command).isEmpty();
+}
+
+} // namespace
+
+QStringList splitDesktopList(const QString &value)
+{
+    const QStringList raw = value.split(QLatin1Char(';'), Qt::SkipEmptyParts);
+    QStringList cleaned;
+    cleaned.reserve(raw.size());
+    for (const QString &item : raw) {
+        const QString trimmed = item.trimmed();
+        if (!trimmed.isEmpty())
+            cleaned.append(trimmed);
+    }
+    return cleaned;
+}
+
+QStringList currentDesktopIdentifiers()
+{
+    const QByteArray raw = qgetenv("XDG_CURRENT_DESKTOP");
+    if (raw.isEmpty())
+        return {QStringLiteral("NebulaOS")};
+
+    QStringList ids;
+    for (const QByteArray &part : raw.split(':')) {
+        const QString id = QString::fromLocal8Bit(part).trimmed();
+        if (!id.isEmpty())
+            ids.append(id);
+    }
+    if (ids.isEmpty())
+        ids.append(QStringLiteral("NebulaOS"));
+    return ids;
+}
+
+QStringList applicationDirectories()
+{
+    QStringList dirs;
+
+    QString dataHome = QString::fromLocal8Bit(qgetenv("XDG_DATA_HOME"));
+    if (dataHome.isEmpty())
+        dataHome = QDir::homePath() + QStringLiteral("/.local/share");
+    dirs.append(QDir::cleanPath(dataHome + QStringLiteral("/applications")));
+
+    QString dataDirs = QString::fromLocal8Bit(qgetenv("XDG_DATA_DIRS"));
+    if (dataDirs.isEmpty())
+        dataDirs = QStringLiteral("/usr/local/share:/usr/share");
+
+    for (const QString &root : dataDirs.split(QLatin1Char(':'), Qt::SkipEmptyParts)) {
+        const QString trimmed = root.trimmed();
+        if (trimmed.isEmpty())
+            continue;
+        dirs.append(QDir::cleanPath(trimmed + QStringLiteral("/applications")));
+    }
+
+    dirs.removeDuplicates();
+    return dirs;
+}
+
+QString resolveIconName(const QString &icon)
+{
+    if (icon.isEmpty())
+        return {};
+
+    const QFileInfo info(icon);
+    if (info.isAbsolute())
+        return icon;
+
+    QString name = icon;
+    if (name.endsWith(QLatin1String(".png"), Qt::CaseInsensitive)
+        || name.endsWith(QLatin1String(".svg"), Qt::CaseInsensitive)
+        || name.endsWith(QLatin1String(".xpm"), Qt::CaseInsensitive)) {
+        name = QFileInfo(name).completeBaseName();
+    }
+    return name;
+}
+
+QStringList expandExec(const QString &exec, const DesktopEntry &entry)
+{
+    QString expanded;
+    expanded.reserve(exec.size());
+
+    for (int i = 0; i < exec.size(); ++i) {
+        const QChar ch = exec.at(i);
+        if (ch != QLatin1Char('%') || i + 1 >= exec.size()) {
+            expanded.append(ch);
+            continue;
+        }
+
+        const QChar code = exec.at(++i);
+        auto trimTrailingSpace = [&expanded]() {
+            if (expanded.endsWith(QLatin1Char(' ')))
+                expanded.chop(1);
+        };
+
+        switch (code.toLatin1()) {
+        case '%':
+            expanded.append(QLatin1Char('%'));
+            break;
+        case 'f':
+        case 'F':
+        case 'u':
+        case 'U':
+        case 'd':
+        case 'D':
+        case 'n':
+        case 'N':
+        case 'v':
+        case 'm':
+            // File/URL/deprecated codes are omitted when launching without arguments.
+            trimTrailingSpace();
+            break;
+        case 'c':
+            expanded.append(QLatin1Char('"'));
+            expanded.append(entry.name);
+            expanded.append(QLatin1Char('"'));
+            break;
+        case 'k':
+            expanded.append(QLatin1Char('"'));
+            expanded.append(entry.filePath);
+            expanded.append(QLatin1Char('"'));
+            break;
+        case 'i':
+            if (!entry.icon.isEmpty()) {
+                expanded.append(QStringLiteral("--icon \""));
+                expanded.append(entry.icon);
+                expanded.append(QLatin1Char('"'));
+            } else {
+                trimTrailingSpace();
+            }
+            break;
+        default:
+            trimTrailingSpace();
+            break;
+        }
+    }
+
+    const QStringList parts = QProcess::splitCommand(expanded.trimmed());
+    return parts;
+}
+
+bool DesktopEntry::isLauncherVisible() const
+{
+    if (hidden || noDisplay)
+        return false;
+    if (exec.trimmed().isEmpty())
+        return false;
+    if (!tryExec.trimmed().isEmpty() && !executableAvailable(tryExec.trimmed()))
+        return false;
+    return true;
+}
+
+bool DesktopEntry::launch() const
+{
+    QStringList args = expandExec(exec, *this);
+    if (args.isEmpty()) {
+        qWarning("nebula: cannot launch %s: empty Exec", qPrintable(desktopId));
+        return false;
+    }
+
+    QString program = args.takeFirst();
+    if (program.isEmpty()) {
+        qWarning("nebula: cannot launch %s: missing program", qPrintable(desktopId));
+        return false;
+    }
+
+    if (terminal) {
+        const QString term = findTerminalEmulator();
+        if (term.isEmpty()) {
+            qWarning("nebula: cannot launch %s: Terminal=true but no terminal emulator was found",
+                     qPrintable(desktopId));
+            return false;
+        }
+        QStringList wrapped;
+        wrapped.append(QStringLiteral("-e"));
+        wrapped.append(program);
+        wrapped.append(args);
+        args = std::move(wrapped);
+        program = term;
+    }
+
+    const QString cwd = workingDirectory.isEmpty() ? QDir::homePath() : workingDirectory;
+    qint64 pid = 0;
+    if (!QProcess::startDetached(program, args, cwd, &pid)) {
+        qWarning("nebula: failed to launch %s (%s)", qPrintable(desktopId), qPrintable(program));
+        return false;
+    }
+
+    qInfo("nebula: launched %s (%s) pid %lld", qPrintable(desktopId), qPrintable(program), static_cast<long long>(pid));
+    return true;
+}
+
+DesktopEntry parseDesktopEntryFile(const QString &filePath, const QString &desktopId)
+{
+    DesktopEntry entry;
+    entry.filePath = filePath;
+    entry.desktopId = desktopId;
+
+    QFile file(filePath);
+    if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
+        return entry;
+
+    LocalizedValue names;
+    LocalizedValue genericNames;
+    LocalizedValue comments;
+    QString type = QStringLiteral("Application");
+    QStringList onlyShowIn;
+    QStringList notShowIn;
+    bool inDesktopEntry = false;
+
+    while (!file.atEnd()) {
+        QString line = QString::fromUtf8(file.readLine());
+        if (!line.isEmpty() && line.back() == QLatin1Char('\n'))
+            line.chop(1);
+        if (!line.isEmpty() && line.back() == QLatin1Char('\r'))
+            line.chop(1);
+
+        const QString trimmed = line.trimmed();
+        if (trimmed.isEmpty() || trimmed.startsWith(QLatin1Char('#')))
+            continue;
+
+        if (trimmed.startsWith(QLatin1Char('[')) && trimmed.endsWith(QLatin1Char(']'))) {
+            inDesktopEntry = (trimmed == QLatin1String("[Desktop Entry]"));
+            continue;
+        }
+        if (!inDesktopEntry)
+            continue;
+
+        const int equals = trimmed.indexOf(QLatin1Char('='));
+        if (equals <= 0)
+            continue;
+
+        const QString key = trimmed.left(equals).trimmed();
+        const QString value = unquote(trimmed.mid(equals + 1));
+
+        if (key == QLatin1String("Type"))
+            type = value;
+        else if (key == QLatin1String("Exec"))
+            entry.exec = value;
+        else if (key == QLatin1String("TryExec"))
+            entry.tryExec = value;
+        else if (key == QLatin1String("Icon"))
+            entry.icon = value;
+        else if (key == QLatin1String("Path"))
+            entry.workingDirectory = value;
+        else if (key == QLatin1String("Categories"))
+            entry.categories = splitDesktopList(value);
+        else if (key == QLatin1String("Terminal"))
+            entry.terminal = parseBool(value);
+        else if (key == QLatin1String("Hidden"))
+            entry.hidden = parseBool(value);
+        else if (key == QLatin1String("NoDisplay"))
+            entry.noDisplay = parseBool(value);
+        else if (key == QLatin1String("OnlyShowIn"))
+            onlyShowIn = splitDesktopList(value);
+        else if (key == QLatin1String("NotShowIn"))
+            notShowIn = splitDesktopList(value);
+        else {
+            storeLocalized(&names, key, QStringLiteral("Name"), value);
+            storeLocalized(&genericNames, key, QStringLiteral("GenericName"), value);
+            storeLocalized(&comments, key, QStringLiteral("Comment"), value);
+        }
+    }
+
+    const QLocale locale = QLocale::system();
+    entry.name = resolveLocalized(names, locale);
+    entry.genericName = resolveLocalized(genericNames, locale);
+    entry.comment = resolveLocalized(comments, locale);
+    entry.icon = resolveIconName(entry.icon);
+
+    if (entry.desktopId.isEmpty())
+        entry.desktopId = QFileInfo(filePath).fileName();
+
+    if (type != QLatin1String("Application")) {
+        entry.hidden = true;
+        return entry;
+    }
+
+    const QStringList desktops = currentDesktopIdentifiers();
+    if (!onlyShowIn.isEmpty()) {
+        bool matched = false;
+        for (const QString &desktop : desktops) {
+            if (onlyShowIn.contains(desktop)) {
+                matched = true;
+                break;
+            }
+        }
+        if (!matched)
+            entry.noDisplay = true;
+    }
+    for (const QString &desktop : desktops) {
+        if (notShowIn.contains(desktop)) {
+            entry.noDisplay = true;
+            break;
+        }
+    }
+
+    return entry;
+}

core/applications/DesktopEntry.hpp

@@ -0,0 +1,31 @@
+#pragma once
+
+#include <QString>
+#include <QStringList>
+
+struct DesktopEntry
+{
+    QString desktopId;
+    QString filePath;
+    QString name;
+    QString genericName;
+    QString comment;
+    QString icon;
+    QString exec;
+    QString tryExec;
+    QString workingDirectory;
+    QStringList categories;
+    bool terminal = false;
+    bool hidden = false;
+    bool noDisplay = false;
+
+    bool isLauncherVisible() const;
+    bool launch() const;
+};
+
+DesktopEntry parseDesktopEntryFile(const QString &filePath, const QString &desktopId);
+QStringList applicationDirectories();
+QStringList currentDesktopIdentifiers();
+QStringList splitDesktopList(const QString &value);
+QStringList expandExec(const QString &exec, const DesktopEntry &entry);
+QString resolveIconName(const QString &icon);

core/applications/README.md

@@ -0,0 +1,18 @@
+# Nebula Applications
+
+Shared C++ service for discovering and launching installed Linux applications from `.desktop` entries.
+
+Desktop and the future Bigscreen shell should both use this library. It has no Desktop-specific QML.
+
+## Behaviour
+
+- Scans XDG application directories (`XDG_DATA_HOME`, `XDG_DATA_DIRS`, with the usual `~/.local/share` and `/usr/share` defaults).
+- Hides entries with `Hidden=true` or `NoDisplay=true`, and respects `OnlyShowIn` / `NotShowIn` / `TryExec`.
+- Exposes a `QAbstractListModel` to QML (`desktopId`, `name`, `genericName`, `comment`, `iconName`, `categories`, `terminal`).
+- Launches with `QProcess::startDetached` and `QProcess::splitCommand`. Does not use a shell.
+- Strips or substitutes common Exec field codes when launching without files/URLs.
+
+QML module URI: `Nebula.Applications`.
+
+See `shells/desktop/README.md` for launcher behaviour and session integration.
+

packages/nebula-ui/qml/Nebula/UI/NebulaIcon.qml

@@ -79,8 +79,11 @@ Item {
         case "document":
             paintDocument(ctx)
             break
+        case "application":
+            paintApplication(ctx)
+            break
         default:
-            paintFolder(ctx)
+            paintApplication(ctx)
             break
         }
     }
@@ -189,6 +192,23 @@ Item {
         ctx.stroke()
     }
 
+    function paintApplication(ctx) {
+        ctx.lineWidth = 1.5
+        ctx.beginPath()
+        roundedRect(ctx, 4.2, 5.2, 15.6, 13.6, 2.2)
+        ctx.stroke()
+        ctx.beginPath()
+        ctx.moveTo(4.2, 8.4)
+        ctx.lineTo(19.8, 8.4)
+        ctx.stroke()
+        ctx.beginPath()
+        ctx.arc(7, 6.8, 0.7, 0, Math.PI * 2)
+        ctx.fill()
+        ctx.beginPath()
+        ctx.arc(9.4, 6.8, 0.7, 0, Math.PI * 2)
+        ctx.fill()
+    }
+
     function paintFolder(ctx) {
         ctx.beginPath()
         ctx.moveTo(3.5, 8.2)

scripts/run-nebula-vm.sh

@@ -0,0 +1,67 @@
+#!/bin/sh
+# VMware / development-only launcher for nebula-shell.
+#
+# The Ubuntu VMware guest GPU cannot currently run the Qt Quick accelerated
+# scene graph correctly. This wrapper sets QT_QUICK_BACKEND=software.
+#
+# Production sessions must start `nebula-shell` directly and must NOT export
+# QT_QUICK_BACKEND. GPU-accelerated Qt Quick is the production default.
+#
+# Usage (from a running Nebula Sway session, or via nebula-sway.conf exec):
+#   scripts/run-nebula-vm.sh
+#
+# Disable autostart:
+#   NEBULA_SHELL_AUTOSTART=0 sway -c compositor/sway/nebula-sway.conf
+
+set -eu
+
+if [ "${NEBULA_SHELL_AUTOSTART:-1}" = "0" ]; then
+    echo "nebula: shell autostart disabled (NEBULA_SHELL_AUTOSTART=0)"
+    exit 0
+fi
+
+script_dir=$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)
+repo_root=$(CDPATH= cd -- "${script_dir}/.." && pwd)
+
+export XCURSOR_THEME="${XCURSOR_THEME:-Adwaita}"
+export XCURSOR_SIZE="${XCURSOR_SIZE:-24}"
+
+# Development-only. Do not copy this into production session files.
+export QT_QUICK_BACKEND="${QT_QUICK_BACKEND:-software}"
+
+resolve_shell() {
+    if [ -n "${NEBULA_SHELL:-}" ] && [ -x "${NEBULA_SHELL}" ]; then
+        printf '%s\n' "${NEBULA_SHELL}"
+        return 0
+    fi
+
+    if command -v nebula-shell >/dev/null 2>&1; then
+        command -v nebula-shell
+        return 0
+    fi
+
+    for candidate in \
+        "${repo_root}/shells/desktop/shell/build/nebula-shell" \
+        "${repo_root}/build/nebula-shell" \
+        "${PWD}/shells/desktop/shell/build/nebula-shell" \
+        "${PWD}/build/nebula-shell"
+    do
+        if [ -x "${candidate}" ]; then
+            printf '%s\n' "${candidate}"
+            return 0
+        fi
+    done
+
+    return 1
+}
+
+if ! shell_bin=$(resolve_shell); then
+    echo "nebula: nebula-shell not found." >&2
+    echo "Build it with:" >&2
+    echo "  cd shells/desktop/shell && cmake -S . -B build && cmake --build build -j\$(nproc)" >&2
+    echo "Or set NEBULA_SHELL to the executable path." >&2
+    exit 1
+fi
+
+echo "nebula: starting ${shell_bin} (QT_QUICK_BACKEND=${QT_QUICK_BACKEND})"
+exec "${shell_bin}" "$@"

session/nebula-session

@@ -1,11 +1,20 @@
 #!/bin/sh
-# NebulaOS session startup
+# NebulaOS production session startup
+#
+# Production must start nebula-shell without QT_QUICK_BACKEND=software.
+# GPU-accelerated Qt Quick is the production default.
+#
+# The Ubuntu VMware development VM is different: use
+# compositor/sway/dev/run-sway-vm.sh (or sway -c compositor/sway/nebula-sway.conf
+# from the repository root) so the development wrapper can set the software
+# scene-graph backend.
 
 set -e
 
 export XDG_CURRENT_DESKTOP=NebulaOS
 export XDG_SESSION_DESKTOP=nebula
+export XCURSOR_THEME="${XCURSOR_THEME:-Adwaita}"
+export XCURSOR_SIZE="${XCURSOR_SIZE:-24}"
 
-# Shell and services are wired here as they land
 # Production desktop chrome: shells/desktop/shell (nebula-shell)
 # exec nebula-shell

shells/desktop/README.md

@@ -1,6 +1,8 @@
 # Nebula Desktop
 
-Production shell for the mouse-and-keyboard NebulaOS desktop.
+Production shell for the mouse-and-keyboard NebulaOS desktop. This is Nebula Desktop **0.1**: a usable session foundation, not only a visual prototype.
+
+The user can enter the development session, use the full output, open the Nebula launcher, and start real installed applications (including Foot) without Sway keyboard shortcuts.
 
 ## Architecture
 
@@ -34,25 +36,15 @@ Qt Quick/QML
 Normal applications remain ordinary Wayland / XWayland clients of the compositor:
 
 ```text
-Normal Application
+Nebula Launcher
+       ↓
+ApplicationService
+       ↓
+application process
        ↓
 Wayland / XWayland
        ↓
-Compositor
+Sway
-        ↓
-GPU
-```
-
-Nebula chrome:
-
-```text
-QML
- ↓
-Qt Quick
- ↓
-Wayland Layer Shell
- ↓
-Compositor
 ```
 
 Games, browsers, terminals, and other apps never pass through Qt Quick.
@@ -64,6 +56,7 @@ Games, browsers, terminals, and other apps never pass through Qt Quick.
 | Language | C++20 |
 | UI | Qt 6, Qt Quick, QML |
 | Layer surfaces | LayerShellQt |
+| Installed apps | `core/applications` (`import Nebula.Applications`) |
 | Build | CMake |
 | Shared design system | `packages/nebula-ui` (`import Nebula.UI`) |
 
@@ -77,9 +70,9 @@ Independent Wayland layer-shell windows:
 
 | Surface | Layer | Role |
 |---------|-------|------|
-| Desktop | `BACKGROUND` | Wallpaper / desktop, no exclusive zone, no keyboard focus |
+| Desktop | `BACKGROUND` | Fills the current output, no exclusive zone, no keyboard focus |
-| Top Bar | `TOP` | 40px bar, exclusive zone, no keyboard focus by default |
+| Top Bar | `TOP` | 40 logical pixels, exclusive zone, spans the output width |
-| Launcher | `OVERLAY` | Hidden until the Nebula button opens it |
+| Launcher | `OVERLAY` | Covers the output below the top bar while open; hidden otherwise |
 
 Stacking:
 
@@ -91,12 +84,33 @@ TOP
     Nebula Top Bar
 
 NORMAL WAYLAND WINDOWS
-    Firefox, Steam, Blender, games, terminals, …
+    Foot, Firefox, applications, games, …
 
 BACKGROUND
     Nebula Desktop
 ```
 
+Surfaces follow the live Wayland output geometry from Qt (`OutputTracker`). They do not assume 1920×1080 or other fixed desktop sizes. If VMware resizes the display, the shell updates.
+
+## Applications
+
+`core/applications` discovers freedesktop `.desktop` entries from XDG data directories:
+
+1. `$XDG_DATA_HOME/applications` (default `~/.local/share/applications`)
+2. `$XDG_DATA_DIRS/applications` (default `/usr/local/share:/usr/share`)
+
+Launcher-visible apps respect `Hidden=true`, `NoDisplay=true`, `OnlyShowIn` / `NotShowIn`, and `TryExec` when present. Localized `Name` values are used when available.
+
+Launching uses `QProcess::startDetached` after `QProcess::splitCommand`. Exec field codes (`%f`, `%F`, `%u`, `%U`, `%i`, `%c`, `%k`, `%%`, …) are handled for launches without file arguments. Desktop-entry strings are never passed to a shell.
+
+Search matches name, generic name, comment, and categories. Searching `term` should find Foot (`GenericName=Terminal`). Searching `firefox` should find Firefox if it is installed.
+
+Application icons use the system icon theme through Qt (`QIcon::fromTheme`). Unresolved icons use a Nebula fallback glyph, not a broken-image placeholder.
+
+The top-bar context text stays **Desktop** in this milestone. Launching an app is not treated as focus; real window tracking comes next.
+
+Mock launcher data remains only as a fallback when no installed applications are discovered.
+
 ## Layout
 
 ```text
@@ -104,12 +118,12 @@ shells/desktop/
 ├── README.md                 this file
 ├── shell/                    production Qt/QML shell
 │   ├── CMakeLists.txt
-│   ├── src/main.cpp
+│   ├── src/
 │   └── qml/
 └── prototype-react/          archived design reference only
 ```
 
-Shared visual language lives in `packages/nebula-ui`, not in Desktop-specific chrome.
+Shared visual language lives in `packages/nebula-ui`. Application discovery lives in `core/applications`.
 
 ## Linux build
 
@@ -126,6 +140,7 @@ sudo apt install \
     qml6-module-org-kde-layershell \
     qml6-module-qtquick \
     qml6-module-qtquick-window \
+    adwaita-icon-theme \
     cmake \
     build-essential
 ```
@@ -135,14 +150,12 @@ Qt 6.4 or newer is required. `loadFromModule` is used on Qt 6.5+.
 ```bash
 cd shells/desktop/shell
 
+rm -rf build
 cmake -S . -B build
 cmake --build build -j$(nproc)
-./build/nebula-shell
 ```
 
-Run inside a Wayland compositor such as Sway (`compositor/sway/nebula-sway.conf`). Sway must not show its own bar.
+The production binary is `shells/desktop/shell/build/nebula-shell`. It does **not** force `QT_QUICK_BACKEND=software`. GPU-accelerated Qt Quick is the production default.
-
-There is no npm server, Vite server, `NEBULA_SHELL_DEV_URL`, WebKitGTK, GTK4, or React involved in running the production shell.
 
 ### QML lint
 
@@ -159,6 +172,91 @@ qmllint \
 
 Do not use ESLint or Oxlint on the production Qt shell.
 
+## Development session (VMware)
+
+From the repository root, the intended flow is:
+
+```bash
+sway -c compositor/sway/nebula-sway.conf
+```
+
+or, recommended on the VM (sets cursor env and starts Sway from the repo root):
+
+```bash
+./compositor/sway/dev/run-sway-vm.sh
+```
+
+That should:
+
+1. start Sway without a Sway bar
+2. autostart `nebula-shell` through `scripts/run-nebula-vm.sh`
+3. fill the current output
+4. show a normal Adwaita 24px cursor
+5. let the Nebula launcher start Foot and other installed apps
+
+Skip autostart while debugging the compositor:
+
+```bash
+NEBULA_SHELL_AUTOSTART=0 sway -c compositor/sway/nebula-sway.conf
+```
+
+### VMware software rendering
+
+The VMware virtual GPU currently cannot run the Qt Quick accelerated path correctly. The **development wrapper** therefore sets:
+
+```bash
+QT_QUICK_BACKEND=software
+```
+
+That variable is not a production default. `scripts/run-nebula-vm.sh` is the only place that sets it automatically. Production `nebula-session` / `nebula-shell` must run GPU-accelerated.
+
+Manual equivalent, if you start the shell yourself:
+
+```bash
+QT_QUICK_BACKEND=software ./build/nebula-shell
+```
+
+### Output / resolution
+
+The development Sway config requests `1920x1080` at scale `1` when that mode exists. If the VM does not advertise it, Sway keeps the preferred mode. This is a development default, not a production requirement.
+
+Inspect outputs and modes:
+
+```bash
+swaymsg -t get_outputs
+```
+
+Set a mode explicitly if needed:
+
+```bash
+swaymsg output <name> mode 1920x1080
+swaymsg output <name> scale 1
+```
+
+In VMware, also set the guest display (or Autofit Guest) so the advertised modes match the host window.
+
+### Cursor
+
+Sway owns the cursor:
+
+```text
+XCURSOR_THEME=Adwaita
+XCURSOR_SIZE=24
+seat * xcursor_theme Adwaita 24
+```
+
+Install `adwaita-icon-theme` if the theme is missing. A branded Nebula cursor is a later task. `WLR_NO_HARDWARE_CURSORS=1` is set only by the VMware Sway wrapper.
+
+### Emergency shortcuts
+
+These remain for development fallback. They are not the normal UX once the GUI launcher works.
+
+| Shortcut | Action |
+|----------|--------|
+| Super+Enter | open Foot |
+| Super+Shift+E | exit Sway |
+| Super+Shift+C | reload Sway config |
+
 ## Design reference
 
 `prototype-react/` is an archived React/Vite UI. It is **not** the production shell. Keep it until the Qt shell reaches visual and behavioural parity, then remove it in a later cleanup.
@@ -167,12 +265,13 @@ Do not use ESLint or Oxlint on the production Qt shell.
 
 Not implemented in this milestone:
 
+- Sway IPC / focused-window tracking
+- workspaces, window overview, dock
 - PipeWire, NetworkManager, BlueZ, UPower
-- D-Bus services
+- notifications, XDG portals, Polkit
-- real `.desktop` discovery or app launching
+- login/lock screen, greetd
-- Sway IPC, workspaces, notifications
-- authentication, greetd, Gamescope
 - a custom Nebula compositor
 - Nebula Bigscreen
+- Gamescope
 
-Those come later. Bigscreen is expected to reuse `Nebula.UI` and shared C++ services with a different interaction model.
+Those come later. Bigscreen is expected to reuse `Nebula.UI` and `Nebula.Applications`.

shells/desktop/shell/CMakeLists.txt

@@ -25,8 +25,15 @@ add_subdirectory(
     "${CMAKE_CURRENT_BINARY_DIR}/nebula-ui"
 )
 
+add_subdirectory(
+    "${CMAKE_CURRENT_SOURCE_DIR}/../../../core/applications"
+    "${CMAKE_CURRENT_BINARY_DIR}/nebula-applications"
+)
+
 qt_add_executable(nebula-shell
     src/main.cpp
+    src/DesktopIconProvider.cpp
+    src/DesktopIconProvider.hpp
 )
 
 set(NEBULA_SHELL_QML_FILES
@@ -65,9 +72,13 @@ qt_add_qml_module(nebula-shell
     VERSION 1.0
     RESOURCE_PREFIX /qt/qml
     QML_FILES ${NEBULA_SHELL_QML_FILES}
+    SOURCES
+        src/OutputTracker.hpp
+        src/OutputTracker.cpp
     DEPENDENCIES
         QtQuick
         Nebula.UI
+        Nebula.Applications
 )
 
 target_link_libraries(nebula-shell
@@ -78,11 +89,15 @@ target_link_libraries(nebula-shell
         Qt6::Quick
         LayerShellQt::Interface
         NebulaUI
+        NebulaApplications
 )
 
 if(TARGET NebulaUIplugin)
     target_link_libraries(nebula-shell PRIVATE NebulaUIplugin)
 endif()
+if(TARGET NebulaApplicationsplugin)
+    target_link_libraries(nebula-shell PRIVATE NebulaApplicationsplugin)
+endif()
 
 set_target_properties(nebula-shell PROPERTIES
     OUTPUT_NAME nebula-shell

shells/desktop/shell/qml/ShellState.qml

@@ -4,6 +4,9 @@ import QtQuick
 
 QtObject {
     property bool launcherOpen: false
+
+    // Focused-window tracking is a later compositor milestone. Launching an
+    // application does not mean it has focus, so this stays "Desktop" for now.
     property string activeApplication: "Desktop"
 
     function openLauncher() {
@@ -17,9 +20,4 @@ QtObject {
     function toggleLauncher() {
         launcherOpen = !launcherOpen
     }
-
-    function launch(name) {
-        activeApplication = name
-        closeLauncher()
-    }
 }

shells/desktop/shell/qml/components/AppItem.qml

@@ -11,6 +11,17 @@ Item {
     readonly property bool rowVariant: variant === "row"
     readonly property int iconSize: rowVariant ? 32 : (variant === "recent" ? 32 : 40)
     readonly property int glyphSize: rowVariant ? 16 : 18
+    readonly property string iconName: item && item.iconName ? item.iconName : ""
+    readonly property string fallbackGlyph: {
+        if (item && item.glyph)
+            return item.glyph
+        if (item && item.kind)
+            return item.kind
+        return "application"
+    }
+    readonly property url iconSource: iconName.length > 0
+        ? ("image://desktopicon/" + encodeURIComponent(iconName))
+        : ""
 
     implicitWidth: rowVariant ? parent ? parent.width : 200 : 90
     implicitHeight: rowVariant ? 48 : 78
@@ -54,9 +65,23 @@ Item {
                 border.width: 1
             }
 
+            Image {
+                id: tileIcon
+                anchors.centerIn: parent
+                width: root.iconSize - 8
+                height: root.iconSize - 8
+                fillMode: Image.PreserveAspectFit
+                asynchronous: true
+                smooth: true
+                cache: true
+                visible: status === Image.Ready
+                source: root.iconSource
+            }
+
             NebulaIcon {
                 anchors.centerIn: parent
-                name: item && item.glyph ? item.glyph : "folder"
+                visible: tileIcon.status !== Image.Ready
+                name: root.fallbackGlyph
                 size: root.glyphSize
                 color: item && item.tint ? item.tint : Theme.accent
             }
@@ -86,9 +111,23 @@ Item {
             anchors.verticalCenter: parent.verticalCenter
             color: Theme.iconWell
 
+            Image {
+                id: rowIcon
+                anchors.centerIn: parent
+                width: root.iconSize - 8
+                height: root.iconSize - 8
+                fillMode: Image.PreserveAspectFit
+                asynchronous: true
+                smooth: true
+                cache: true
+                visible: status === Image.Ready
+                source: root.iconSource
+            }
+
             NebulaIcon {
                 anchors.centerIn: parent
-                name: item && (item.glyph || item.kind) ? (item.glyph || item.kind) : "folder"
+                visible: rowIcon.status !== Image.Ready
+                name: root.fallbackGlyph
                 size: root.glyphSize
                 color: item && item.tint ? item.tint : Theme.accent
             }

shells/desktop/shell/qml/components/Launcher.qml

@@ -1,5 +1,6 @@
 import QtQuick
 import Nebula.UI
+import Nebula.Applications
 
 Item {
     id: root
@@ -13,8 +14,9 @@ Item {
     Accessible.role: Accessible.Dialog
     Accessible.name: qsTr("Launcher")
 
+    readonly property bool usingInstalledApps: ApplicationService.count > 0
     readonly property bool searching: searchField.text.trim().length > 0
-    readonly property var filteredApps: {
+    readonly property var mockMatches: {
         const query = searchField.text.trim().toLowerCase()
         const apps = MockApps.apps
         if (!query)
@@ -24,6 +26,9 @@ Item {
             return haystack.indexOf(query) !== -1
         })
     }
+    readonly property int resultCount: usingInstalledApps
+        ? ApplicationService.filteredModel.count
+        : mockMatches.length
 
     Keys.onEscapePressed: {
         event.accepted = true
@@ -62,6 +67,7 @@ Item {
             id: searchField
             width: parent.width
             placeholderText: qsTr("Search applications")
+            onTextChanged: ApplicationService.filter = text
         }
 
         Item {
@@ -87,7 +93,7 @@ Item {
                 Column {
                     width: parent.width
                     spacing: 8
-                    visible: !root.searching && MockApps.recents.length > 0
+                    visible: !root.searching && !root.usingInstalledApps && MockApps.recents.length > 0
 
                     Text {
                         text: qsTr("Recent")
@@ -133,14 +139,33 @@ Item {
 
                     Grid {
                         id: appGrid
-                        visible: root.filteredApps.length > 0
+                        visible: root.resultCount > 0
                         width: parent.width
                         columns: 4
                         columnSpacing: 6
                         rowSpacing: 6
 
                         Repeater {
-                            model: root.filteredApps
+                            model: root.usingInstalledApps ? ApplicationService.filteredModel : []
+                            delegate: AppItem {
+                                required property string desktopId
+                                required property string name
+                                required property string comment
+                                required property string iconName
+                                width: (appGrid.width - 18) / 4
+                                variant: "tile"
+                                item: ({
+                                    desktopId: desktopId,
+                                    name: name,
+                                    comment: comment,
+                                    iconName: iconName
+                                })
+                                onSelected: root.launchApp(item)
+                            }
+                        }
+
+                        Repeater {
+                            model: root.usingInstalledApps ? [] : root.mockMatches
                             delegate: AppItem {
                                 required property var modelData
                                 width: (appGrid.width - 18) / 4
@@ -152,7 +177,7 @@ Item {
                     }
 
                     Text {
-                        visible: root.filteredApps.length === 0
+                        visible: root.resultCount === 0
                         width: parent.width
                         topPadding: 8
                         text: qsTr("No matching applications")
@@ -165,7 +190,7 @@ Item {
                 Column {
                     width: parent.width
                     spacing: 8
-                    visible: !root.searching && MockApps.projects.length > 0
+                    visible: !root.searching && !root.usingInstalledApps && MockApps.projects.length > 0
 
                     Text {
                         text: qsTr("Recent projects")
@@ -286,10 +311,12 @@ Item {
     }
 
     function launchApp(app) {
-        ShellState.launch(app.name)
+        if (app && app.desktopId)
+            ApplicationService.launch(app.desktopId)
+        ShellState.closeLauncher()
     }
 
     function openProject(project) {
-        ShellState.launch(project.name)
+        ShellState.closeLauncher()
     }
 }

shells/desktop/shell/qml/surfaces/DesktopSurface.qml

@@ -6,12 +6,19 @@ import Nebula.UI
 Window {
     id: root
 
+    readonly property int outputWidth: OutputTracker.width > 0
+        ? OutputTracker.width
+        : (screen && screen.width > 0 ? screen.width : Screen.width)
+    readonly property int outputHeight: OutputTracker.height > 0
+        ? OutputTracker.height
+        : (screen && screen.height > 0 ? screen.height : Screen.height)
+
     title: qsTr("Nebula Desktop")
     color: "transparent"
     flags: Qt.FramelessWindowHint | Qt.WindowDoesNotAcceptFocus
     visible: true
-    width: Screen.width
+    width: outputWidth
-    height: Screen.height
+    height: outputHeight
 
     LayerShell.Window.scope: "nebula-desktop"
     LayerShell.Window.layer: LayerShell.Window.LayerBackground

shells/desktop/shell/qml/surfaces/LauncherSurface.qml

@@ -6,12 +6,19 @@ import Nebula.UI
 Window {
     id: root
 
+    readonly property int outputWidth: OutputTracker.width > 0
+        ? OutputTracker.width
+        : (screen && screen.width > 0 ? screen.width : Screen.width)
+    readonly property int outputHeight: OutputTracker.height > 0
+        ? OutputTracker.height
+        : (screen && screen.height > 0 ? screen.height : Screen.height)
+
     title: qsTr("Nebula Launcher")
     color: "transparent"
     flags: Qt.FramelessWindowHint
     visible: ShellState.launcherOpen || launcher.opacity > 0.01
-    width: Screen.width
+    width: outputWidth
-    height: Screen.height - Theme.topBarHeight
+    height: Math.max(1, outputHeight - Theme.topBarHeight)
 
     LayerShell.Window.scope: "nebula-launcher"
     LayerShell.Window.layer: LayerShell.Window.LayerOverlay

shells/desktop/shell/qml/surfaces/TopBarSurface.qml

@@ -6,11 +6,15 @@ import Nebula.UI
 Window {
     id: root
 
+    readonly property int outputWidth: OutputTracker.width > 0
+        ? OutputTracker.width
+        : (screen && screen.width > 0 ? screen.width : Screen.width)
+
     title: qsTr("Nebula Top Bar")
     color: "transparent"
     flags: Qt.FramelessWindowHint | Qt.WindowDoesNotAcceptFocus
     visible: true
-    width: Screen.width
+    width: outputWidth
     height: Theme.topBarHeight
 
     LayerShell.Window.scope: "nebula-topbar"

shells/desktop/shell/src/DesktopIconProvider.cpp

@@ -0,0 +1,87 @@
+#include "DesktopIconProvider.hpp"
+
+#include <QFileInfo>
+#include <QIcon>
+#include <QPixmap>
+#include <QUrl>
+
+namespace {
+
+QIcon resolveDesktopIcon(const QString &name)
+{
+    if (name.isEmpty())
+        return {};
+
+    const QFileInfo direct(name);
+    if (direct.isAbsolute() && direct.exists())
+        return QIcon(name);
+
+    QIcon themed = QIcon::fromTheme(name);
+    if (!themed.isNull())
+        return themed;
+
+    QString base = name;
+    if (base.endsWith(QLatin1String(".png"), Qt::CaseInsensitive)
+        || base.endsWith(QLatin1String(".svg"), Qt::CaseInsensitive)
+        || base.endsWith(QLatin1String(".xpm"), Qt::CaseInsensitive)) {
+        base = QFileInfo(base).completeBaseName();
+        themed = QIcon::fromTheme(base);
+        if (!themed.isNull())
+            return themed;
+    }
+
+    const QStringList pixmapDirs = {
+        QStringLiteral("/usr/share/pixmaps"),
+        QStringLiteral("/usr/share/icons/hicolor/48x48/apps"),
+        QStringLiteral("/usr/share/icons/hicolor/scalable/apps"),
+    };
+    const QStringList suffixes = {
+        QString(),
+        QStringLiteral(".png"),
+        QStringLiteral(".svg"),
+        QStringLiteral(".xpm"),
+    };
+
+    for (const QString &dir : pixmapDirs) {
+        for (const QString &suffix : suffixes) {
+            const QString candidate = dir + QLatin1Char('/') + (suffix.isEmpty() ? name : base) + suffix;
+            if (QFileInfo::exists(candidate))
+                return QIcon(candidate);
+        }
+    }
+
+    return {};
+}
+
+} // namespace
+
+DesktopIconProvider::DesktopIconProvider()
+    : QQuickImageProvider(QQuickImageProvider::Pixmap)
+{
+}
+
+QPixmap DesktopIconProvider::requestPixmap(const QString &id, QSize *size, const QSize &requestedSize)
+{
+    const QString iconName = QUrl::fromPercentEncoding(id.toUtf8());
+    const QIcon icon = resolveDesktopIcon(iconName);
+    const QSize target = requestedSize.isValid() && requestedSize.width() > 0 && requestedSize.height() > 0
+        ? requestedSize
+        : QSize(48, 48);
+
+    if (icon.isNull()) {
+        if (size)
+            *size = target;
+        return {};
+    }
+
+    const QPixmap pixmap = icon.pixmap(target);
+    if (pixmap.isNull()) {
+        if (size)
+            *size = target;
+        return {};
+    }
+
+    if (size)
+        *size = pixmap.size();
+    return pixmap;
+}

shells/desktop/shell/src/DesktopIconProvider.hpp

@@ -0,0 +1,10 @@
+#pragma once
+
+#include <QQuickImageProvider>
+
+class DesktopIconProvider : public QQuickImageProvider
+{
+public:
+    DesktopIconProvider();
+    QPixmap requestPixmap(const QString &id, QSize *size, const QSize &requestedSize) override;
+};

shells/desktop/shell/src/OutputTracker.cpp

@@ -0,0 +1,91 @@
+#include "OutputTracker.hpp"
+
+#include <QCoreApplication>
+#include <QGuiApplication>
+#include <QJSEngine>
+#include <QRect>
+
+OutputTracker::OutputTracker(QObject *parent)
+    : QObject(parent)
+{
+    if (auto *app = qobject_cast<QGuiApplication *>(QCoreApplication::instance())) {
+        connect(app, &QGuiApplication::primaryScreenChanged, this, [this](QScreen *screen) {
+            bindScreen(screen);
+        });
+        connect(app, &QGuiApplication::screenAdded, this, [this](QScreen *) {
+            if (!m_screen)
+                bindScreen(QGuiApplication::primaryScreen());
+        });
+        connect(app, &QGuiApplication::screenRemoved, this, [this](QScreen *screen) {
+            if (m_screen == screen)
+                bindScreen(QGuiApplication::primaryScreen());
+        });
+        bindScreen(app->primaryScreen());
+    }
+}
+
+OutputTracker *OutputTracker::create(QQmlEngine *engine, QJSEngine *)
+{
+    auto *tracker = new OutputTracker(engine);
+    QQmlEngine::setObjectOwnership(tracker, QQmlEngine::CppOwnership);
+    return tracker;
+}
+
+void OutputTracker::bindScreen(QScreen *screen)
+{
+    if (m_screen == screen)
+        return;
+
+    if (m_screen) {
+        disconnect(m_screen, nullptr, this, nullptr);
+    }
+
+    m_screen = screen;
+    if (m_screen) {
+        connect(m_screen, &QScreen::geometryChanged, this, [this](const QRect &) {
+            logGeometry();
+            emit geometryChanged();
+        });
+        connect(m_screen, &QScreen::physicalDotsPerInchChanged, this, &OutputTracker::geometryChanged);
+    }
+
+    logGeometry();
+    emit geometryChanged();
+}
+
+void OutputTracker::logGeometry() const
+{
+    if (!m_screen) {
+        qWarning("nebula-shell: no Wayland output is available yet");
+        return;
+    }
+
+    const QRect geo = m_screen->geometry();
+    qInfo("nebula-shell: output %s %dx%d+%d+%d scale %g",
+          qPrintable(m_screen->name()),
+          geo.width(),
+          geo.height(),
+          geo.x(),
+          geo.y(),
+          m_screen->devicePixelRatio());
+}
+
+int OutputTracker::width() const
+{
+    return m_screen ? m_screen->geometry().width() : 0;
+}
+
+int OutputTracker::height() const
+{
+    return m_screen ? m_screen->geometry().height() : 0;
+}
+
+qreal OutputTracker::devicePixelRatio() const
+{
+    return m_screen ? m_screen->devicePixelRatio() : 1.0;
+}
+
+QString OutputTracker::name() const
+{
+    return m_screen ? m_screen->name() : QString();
+}

shells/desktop/shell/src/OutputTracker.hpp

@@ -0,0 +1,38 @@
+#pragma once
+
+#include <QObject>
+#include <QPointer>
+#include <QQmlEngine>
+#include <QScreen>
+#include <QtQml/qqmlregistration.h>
+
+class QJSEngine;
+
+class OutputTracker : public QObject
+{
+    Q_OBJECT
+    QML_ELEMENT
+    QML_SINGLETON
+    Q_PROPERTY(int width READ width NOTIFY geometryChanged)
+    Q_PROPERTY(int height READ height NOTIFY geometryChanged)
+    Q_PROPERTY(qreal devicePixelRatio READ devicePixelRatio NOTIFY geometryChanged)
+    Q_PROPERTY(QString name READ name NOTIFY geometryChanged)
+
+public:
+    explicit OutputTracker(QObject *parent = nullptr);
+    static OutputTracker *create(QQmlEngine *engine, QJSEngine *scriptEngine);
+
+    int width() const;
+    int height() const;
+    qreal devicePixelRatio() const;
+    QString name() const;
+
+signals:
+    void geometryChanged();
+
+private:
+    void bindScreen(QScreen *screen);
+    void logGeometry() const;
+
+    QPointer<QScreen> m_screen;
+};

shells/desktop/shell/src/main.cpp

@@ -1,11 +1,48 @@
+#include "DesktopIconProvider.hpp"
+
 #include <LayerShellQt/Shell>
 
+#include <QCoreApplication>
+#include <QDir>
 #include <QGuiApplication>
+#include <QIcon>
 #include <QQmlApplicationEngine>
 #include <QQuickWindow>
 #include <QUrl>
 #include <QtGlobal>
 
+namespace {
+
+void initializeIconTheme()
+{
+    if (QIcon::themeName().isEmpty()) {
+        const QStringList candidates = {
+            QStringLiteral("Adwaita"),
+            QStringLiteral("Yaru"),
+            QStringLiteral("ubuntu-mono-dark"),
+            QStringLiteral("breeze"),
+            QStringLiteral("hicolor"),
+        };
+
+        const QStringList searchPaths = QIcon::themeSearchPaths();
+        for (const QString &theme : candidates) {
+            for (const QString &root : searchPaths) {
+                if (QDir(root + QLatin1Char('/') + theme).exists()) {
+                    QIcon::setThemeName(theme);
+                    break;
+                }
+            }
+            if (!QIcon::themeName().isEmpty())
+                break;
+        }
+    }
+
+    if (QIcon::fallbackThemeName().isEmpty())
+        QIcon::setFallbackThemeName(QStringLiteral("hicolor"));
+}
+
+} // namespace
+
 int main(int argc, char *argv[])
 {
     LayerShellQt::Shell::useLayerShell();
@@ -16,10 +53,12 @@ int main(int argc, char *argv[])
     app.setOrganizationName(QStringLiteral("NebulaOS"));
     app.setDesktopFileName(QStringLiteral("org.nebulaos.shell"));
 
+    initializeIconTheme();
     QQuickWindow::setDefaultAlphaBuffer(true);
 
     QQmlApplicationEngine engine;
     engine.addImportPath(QStringLiteral("qrc:/qt/qml"));
+    engine.addImageProvider(QStringLiteral("desktopicon"), new DesktopIconProvider);
 
     QObject::connect(
         &engine,