diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index c2e2baa..4eb8d51 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -48,6 +48,10 @@ jobs:
           binary=$(find dist -maxdepth 1 -type f -name '*.bin' -print -quit)
           test -n "${binary}"
           test -x "${binary}"
+          version=$(sed -n '/^\[workspace\.package\]$/,/^\[/ { s/^version = "\([^"]*\)"/\1/p; }' Cargo.toml)
+          reported_source=$("${binary}" --source | head -n 1)
+          test "${reported_source}" = \
+            "OneNote Viewer ${version} source revision: ${GITHUB_SHA}"
           G_DEBUG=fatal-warnings \
             GTK_A11Y=none \
             GSK_RENDERER=cairo \
@@ -73,8 +77,13 @@ jobs:
         run: |
           version=$(sed -n '/^\[workspace\.package\]$/,/^\[/ { s/^version = "\([^"]*\)"/\1/p; }' Cargo.toml)
           test -n "${version}"
+          mkdir -p target/flatpak
+          ONENOTE_VIEWER_SOURCE_REVISION="${GITHUB_SHA}" \
+            ./scripts/source-revision.sh > target/flatpak/source-revision
+          revision=$(cat target/flatpak/source-revision)
           echo "version=${version}" >> "${GITHUB_OUTPUT}"
           echo "bundle=OneNoteViewer-${version}-linux-x86_64.flatpak" >> "${GITHUB_OUTPUT}"
+          echo "revision=${revision}" >> "${GITHUB_OUTPUT}"
 
       - name: Build Flatpak bundle
         uses: flatpak/flatpak-github-actions/flatpak-builder@401fe28a8384095fc1531b9d320b292f0ee45adb
@@ -88,6 +97,7 @@ jobs:
       - name: Verify bundled application and extractor
         env:
           BUNDLE: ${{ steps.release.outputs.bundle }}
+          REVISION: ${{ steps.release.outputs.revision }}
           VERSION: ${{ steps.release.outputs.version }}
         run: |
           flatpak install --noninteractive "./${BUNDLE}"
@@ -97,6 +107,10 @@ jobs:
           reported_version=$(flatpak run io.github.emsi.OneNoteViewer --version |
             head -n 1)
           test "${reported_version}" = "OneNote Viewer ${VERSION}"
+          reported_source=$(flatpak run io.github.emsi.OneNoteViewer --source |
+            head -n 1)
+          test "${reported_source}" = \
+            "OneNote Viewer ${VERSION} source revision: ${REVISION}"
           flatpak run --command=7zz io.github.emsi.OneNoteViewer i |
             grep 'Cab' >/dev/null
           xvfb-run -a \
@@ -154,6 +168,11 @@ jobs:
           test -n "${appimage}"
           test -x "${appimage}"
           APPIMAGE_EXTRACT_AND_RUN=1 "${appimage}" --version
+          reported_source=$(APPIMAGE_EXTRACT_AND_RUN=1 "${appimage}" --source |
+            head -n 1)
+          version=$(sed -n '/^\[workspace\.package\]$/,/^\[/ { s/^version = "\([^"]*\)"/\1/p; }' Cargo.toml)
+          test "${reported_source}" = \
+            "OneNote Viewer ${version} source revision: ${GITHUB_SHA}"
           APPIMAGE_EXTRACT_AND_RUN=1 \
             G_DEBUG=fatal-warnings \
             GTK_A11Y=none \
diff --git a/crates/onenote-viewer/src/app.rs b/crates/onenote-viewer/src/app.rs
index ef672fa..0b2ec7f 100644
--- a/crates/onenote-viewer/src/app.rs
+++ b/crates/onenote-viewer/src/app.rs
@@ -339,6 +339,7 @@ impl Viewer {
         let open_folder = gio::SimpleAction::new("open-folder", None);
         let import_package = gio::SimpleAction::new("import-package", None);
         let open_settings = gio::SimpleAction::new("settings", None);
+        let show_about = gio::SimpleAction::new("about", None);
         let quit = gio::SimpleAction::new("quit", None);
         let close_source = icon_button("onenote-close-symbolic", "Close selected notebook");
         let spinner = gtk::Spinner::new();
@@ -362,6 +363,9 @@ impl Viewer {
         let preferences_menu = gio::Menu::new();
         preferences_menu.append(Some("Settings"), Some("win.settings"));
         application_menu.append_section(None, &preferences_menu);
+        let information_menu = gio::Menu::new();
+        information_menu.append(Some("About OneNote Viewer"), Some("win.about"));
+        application_menu.append_section(None, &information_menu);
         let quit_menu = gio::Menu::new();
         quit_menu.append(Some("Quit OneNote Viewer"), Some("win.quit"));
         application_menu.append_section(None, &quit_menu);
@@ -606,6 +610,7 @@ impl Viewer {
         viewer.window.add_action(&open_folder);
         viewer.window.add_action(&import_package);
         viewer.window.add_action(&open_settings);
+        viewer.window.add_action(&show_about);
         viewer.window.add_action(&quit);
         application.set_accels_for_action("win.open-file", &["<Primary>o"]);
         application.set_accels_for_action("win.open-folder", &["<Primary><Shift>o"]);
@@ -620,6 +625,7 @@ impl Viewer {
             &quit,
             &close_source,
         );
+        viewer.connect_about(&show_about);
         viewer.connect_system_theme();
         viewer.connect_import_activity();
         viewer.connect_zoom(&zoom_out, &zoom_in, &zoom_reset);
@@ -727,6 +733,15 @@ impl Viewer {
         });
     }
 
+    fn connect_about(self: &Rc<Self>, show_about: &gio::SimpleAction) {
+        let weak = Rc::downgrade(self);
+        show_about.connect_activate(move |_, _| {
+            if let Some(viewer) = weak.upgrade() {
+                crate::dialogs::present_about(&viewer.window);
+            }
+        });
+    }
+
     fn connect_system_theme(self: &Rc<Self>) {
         let Some(settings) = gtk::Settings::default() else {
             return;
diff --git a/crates/onenote-viewer/src/dialogs.rs b/crates/onenote-viewer/src/dialogs.rs
index 90da3f2..618bb70 100644
--- a/crates/onenote-viewer/src/dialogs.rs
+++ b/crates/onenote-viewer/src/dialogs.rs
@@ -7,6 +7,30 @@ use std::rc::Rc;
 
 type ErrorHandler = Rc<dyn Fn(&str, &str)>;
 
+pub(crate) fn present_about(parent_window: &gtk::ApplicationWindow) {
+    let system_information = format!(
+        "Version: {}\nSource revision: {}\nApplication ID: io.github.emsi.OneNoteViewer",
+        env!("CARGO_PKG_VERSION"),
+        crate::SOURCE_REVISION,
+    );
+    let dialog = gtk::AboutDialog::builder()
+        .transient_for(parent_window)
+        .modal(true)
+        .program_name("OneNote Viewer")
+        .version(env!("CARGO_PKG_VERSION"))
+        .comments("A native Linux viewer for local Microsoft OneNote notebooks.")
+        .copyright("Copyright (c) 2026 Mariusz Woloszyn")
+        .authors(["Mariusz Woloszyn"])
+        .license_type(gtk::License::Gpl30)
+        .logo_icon_name("io.github.emsi.OneNoteViewer")
+        .website("https://github.com/emsi/OneNoteViewer")
+        .website_label("Project website")
+        .system_information(system_information)
+        .build();
+    dialog.add_css_class("settings-dialog");
+    dialog.present();
+}
+
 #[allow(clippy::too_many_lines)]
 pub(crate) fn present_package_import<F, E>(
     parent_window: &gtk::ApplicationWindow,
diff --git a/packaging/flatpak/io.github.emsi.OneNoteViewer.yml b/packaging/flatpak/io.github.emsi.OneNoteViewer.yml
index dff6bd2..a15558c 100644
--- a/packaging/flatpak/io.github.emsi.OneNoteViewer.yml
+++ b/packaging/flatpak/io.github.emsi.OneNoteViewer.yml
@@ -40,7 +40,9 @@ modules:
         CARGO_NET_OFFLINE: 'true'
     build-commands:
       - install -Dm0644 cargo/config .cargo/config.toml
-      - cargo build --offline --frozen --release -p onenote-viewer
+      - >-
+        ONENOTE_VIEWER_SOURCE_REVISION="$(cat onenote-viewer-source-revision)"
+        cargo build --offline --frozen --release -p onenote-viewer
       - install -Dm0755 target/release/onenote-viewer /app/bin/onenote-viewer
       - install -Dm0644 packaging/flatpak/io.github.emsi.OneNoteViewer.desktop /app/share/applications/io.github.emsi.OneNoteViewer.desktop
       - install -Dm0644 packaging/flatpak/io.github.emsi.OneNoteViewer.metainfo.xml /app/share/metainfo/io.github.emsi.OneNoteViewer.metainfo.xml
@@ -62,4 +64,7 @@ modules:
           - onepkg
           - target
           - test-corpus
+      - type: file
+        path: ../../target/flatpak/source-revision
+        dest-filename: onenote-viewer-source-revision
       - cargo-sources.json
diff --git a/scripts/build-appimage-release.sh b/scripts/build-appimage-release.sh
index 04bf3b5..9e34657 100755
--- a/scripts/build-appimage-release.sh
+++ b/scripts/build-appimage-release.sh
@@ -1,7 +1,7 @@
 #!/bin/sh
 set -eu
 
-root=$(CDPATH= cd -- "$(dirname -- "$0")/.." && pwd)
+root=$(CDPATH='' cd -- "$(dirname -- "$0")/.." && pwd)
 cd "$root"
 
 for command in cargo curl file glib-compile-schemas install pkg-config sha256sum; do
@@ -30,6 +30,7 @@ if [ -z "$version" ]; then
     printf '%s\n' 'could not determine workspace version' >&2
     exit 1
 fi
+revision=$(./scripts/source-revision.sh)
 
 linuxdeploy_url=https://github.com/linuxdeploy/linuxdeploy/releases/download/1-alpha-20251107-1/linuxdeploy-x86_64.AppImage
 linuxdeploy_sha256=c20cd71e3a4e3b80c3483cef793cda3f4e990aca14014d23c544ca3ce1270b4d
@@ -73,7 +74,8 @@ download_verified "$sevenzip_source_url" "$sevenzip_source" "$sevenzip_source_sh
 chmod +x "$linuxdeploy" "$appimagetool"
 
 cargo fetch --locked
-cargo build --offline --frozen --locked --release -p onenote-viewer
+ONENOTE_VIEWER_SOURCE_REVISION="$revision" \
+    cargo build --offline --frozen --locked --release -p onenote-viewer
 
 rm -rf "$appdir"
 mkdir -p \
diff --git a/scripts/build-flatpak-release.sh b/scripts/build-flatpak-release.sh
index 76a4b20..796c9fc 100755
--- a/scripts/build-flatpak-release.sh
+++ b/scripts/build-flatpak-release.sh
@@ -1,7 +1,7 @@
 #!/bin/sh
 set -eu
 
-root=$(CDPATH= cd -- "$(dirname -- "$0")/.." && pwd)
+root=$(CDPATH='' cd -- "$(dirname -- "$0")/.." && pwd)
 cd "$root"
 
 for command in flatpak flatpak-builder; do
@@ -41,6 +41,10 @@ manifest=packaging/flatpak/io.github.emsi.OneNoteViewer.yml
 build_dir=target/flatpak/build
 repo_dir=target/flatpak/repo
 bundle="dist/OneNoteViewer-${version}-linux-${arch}.flatpak"
+revision_file=target/flatpak/source-revision
+
+mkdir -p "$(dirname "$revision_file")" dist
+./scripts/source-revision.sh >"$revision_file"
 
 flatpak remote-add \
     --user \
@@ -56,7 +60,6 @@ flatpak-builder \
     --repo="$repo_dir" \
     "$build_dir" \
     "$manifest"
-mkdir -p dist
 flatpak build-bundle \
     "$repo_dir" \
     "$bundle" \
diff --git a/scripts/package-native-release.sh b/scripts/package-native-release.sh
index 44d68ab..9310cd1 100755
--- a/scripts/package-native-release.sh
+++ b/scripts/package-native-release.sh
@@ -1,7 +1,7 @@
 #!/bin/sh
 set -eu
 
-root=$(CDPATH= cd -- "$(dirname -- "$0")/.." && pwd)
+root=$(CDPATH='' cd -- "$(dirname -- "$0")/.." && pwd)
 cd "$root"
 
 case "$(uname -m)" in
@@ -28,10 +28,11 @@ if ! git diff --quiet || ! git diff --cached --quiet; then
         'native releases require a committed source tree so the source archive matches the binary' >&2
     exit 1
 fi
-revision=$(git rev-parse --verify HEAD)
+revision=$(./scripts/source-revision.sh)
 
 ./scripts/check-licenses.sh
-cargo build --locked --release -p onenote-viewer
+ONENOTE_VIEWER_SOURCE_REVISION="$revision" \
+    cargo build --locked --release -p onenote-viewer
 
 archive="OneNoteViewer-${version}-linux-${arch}.tar.gz"
 executable="OneNoteViewer-${version}-linux-${arch}.bin"
diff --git a/scripts/source-revision.sh b/scripts/source-revision.sh
new file mode 100755
index 0000000..961fadd
--- /dev/null
+++ b/scripts/source-revision.sh
@@ -0,0 +1,32 @@
+#!/bin/sh
+set -eu
+
+root=$(CDPATH='' cd -- "$(dirname -- "$0")/.." && pwd)
+revision=${ONENOTE_VIEWER_SOURCE_REVISION:-}
+
+if [ -z "$revision" ]; then
+    revision=$(git -C "$root" rev-parse --verify HEAD)
+    if ! git -C "$root" diff --quiet || ! git -C "$root" diff --cached --quiet; then
+        revision="${revision}-dirty"
+    fi
+fi
+
+case "$revision" in
+    *-dirty) object_id=${revision%-dirty} ;;
+    *) object_id=$revision ;;
+esac
+case "${#object_id}" in
+    40|64) ;;
+    *)
+        printf 'invalid source revision: %s\n' "$revision" >&2
+        exit 1
+        ;;
+esac
+case "$object_id" in
+    ''|*[!0-9a-f]*)
+        printf 'invalid source revision: %s\n' "$revision" >&2
+        exit 1
+        ;;
+esac
+
+printf '%s\n' "$revision"