RetroFind

A native macOS file manager in the style of the Finder of OS X 10.8 Mountain Lion – skeuomorphic Aqua chrome, four views, sidebar, search and Quick Look – working on your real files (no mock-up), plus an optional X-Mode for power users: tabs or dual pane, batch rename, a transfer queue and more.

Swift 5.9 · AppKit · macOS 14 or later · Apple Silicon and Intel · English and German · GPL-3.0

Note: RetroFind is a non-commercial fan project, made out of respect for Apple. It is an independent project and is not affiliated with Apple Inc. The design is inspired by OS X 10.8. Apple, Mac, macOS, OS X, Finder and Mountain Lion are trademarks of Apple Inc.

Features

• Four views – icons (free placement or grid, grouping), list (expandable folders, sortable/movable/resizable columns), columns (preview column) and Cover Flow (perspective covers with reflections, synchronized list).
• Window like the original – 55 pt title bar + toolbar, 136 pt sidebar, status and path bar, toolbar overflow (»), customizable toolbar, minimum window size, zoom to ideal size. System traffic lights by default, optional Aqua traffic lights (Ø 12 pt) in the preferences.
• Sidebar – Favorites, Shared (Bonjour servers), Devices (with eject), Search For; add folders by dropping them, reorder, drag out to remove, collapse and reorder groups. Own-drawn monochrome icons or colored icons (setting), and every sidebar icon can be replaced on the Custom Icons preferences page (PNG, transparent, 64 × 64).
• File operations – copy/move with metadata preserved (copyfile), conflict dialog (replace / keep both / merge / skip), progress with cancel, undo/redo, duplicate, real aliases, ZIP, Trash with Put Back, burn folders.
• Search – Spotlight search bar (This Mac / folder / shared), criteria (kind, name, contents, dates, size, label), smart folders (.savedSearch), All My Files.
• Info & more – Get Info with sections and inspector, colour labels, Spotlight comments, Open With, permissions, Quick Look, Share menu, AirDrop hand-off, Connect to Server, preferences (General, Labels, Sidebar, Advanced), view options (⌘J).
• File display options (General) – show ~/Library, show hidden files, always show folders on top.
• Menus – Finder, File, Edit, View, Go (⌥ reveals Library), Window, Help, with the historical shortcuts.

X-Mode (Preferences ▸ X-Mode)

• Tabs or dual pane (radio buttons). Tabs: ⌘T new, ⌘W close, ⇧⌘[ / ⇧⌘] switch, ⌥⌘1…9 jump, ⇧⌘T reopen closed tab, drag to reorder, tabs restored after relaunch; the active tab merges seamlessly into the toolbar.
• Dual pane – two full panes side by side with a footer: F5 Copy · F6 Move · F7 New Folder · F8 Delete (keys and buttons), Tab switches the active pane, ⌥⌘P toggles, ⌥⌘= mirrors the other pane, ⌥⌘X swaps panes, select/deselect by pattern (⌘+ / ⌘−).
• Per-pane history (⌥↓ or the clock button) and per-pane favorites (⌥⌘B or the star button, drop folders onto the star).
• Transfer queue (⌥⌘Q) – sequential copy/move jobs with progress, speed, remaining time, pause, per-job cancel, conflict policy (ask / replace / keep both / skip / only newer) and optional verification (size + SHA-256).
• Batch rename (⌥⌘R) – replace, add text, number/format ({name} {n}), change case, regular expression; live preview with conflict detection; one undo step.
• Folder sizes on demand (⌥⇧⌘S or Calculate Size in the context menu), Terminal Here (⇧⌥⌘T, choose your terminal app), Copy Path (⌥⌘C).
• Custom app icon (Preferences ▸ Advanced) – any PNG of exactly 256 × 256 pixels.
• Custom Icons (Preferences ▸ Custom Icons) – swap any sidebar icon: choose or drop a transparent 64 × 64 PNG per row, export editable templates, import a folder of <key>.png files, reset one or all.

Screenshots

List (⌘2)	Columns (⌘3)
Cover Flow (⌘4)	Get Info (⌘I)
X-Mode: tabs	X-Mode: dual pane
Preferences ▸ Custom Icons

All images show synthetic demo data (Reference/make_demo.py, run with -demo), taken with the Aqua traffic lights enabled.

Installation

Download the signed and notarized DMG from the latest release, open it and drag the app to Applications. Requires macOS 14 or later (Apple Silicon and Intel). On first launch macOS asks for access to folders such as Desktop, Documents and Downloads.

Build from source

./build.sh          # universal (arm64 + x86_64) → build/RetroFind.app (signed with your Apple Development identity or ad-hoc)
./release.sh        # Developer ID + hardened runtime → notarize → DMG (add "publish" for a GitHub release)
python3 Reference/make_icon.py              # redraw the original app icon → Resources/AppIcon.icns
python3 Reference/make_demo.py              # synthetic demo data for screenshots (/tmp/mlf-demo)

release.sh needs a “Developer ID Application” certificate in the keychain and a notarytool profile (NOTARY_PROFILE, default Retromac). HARDENED=1 ./build.sh signs with hardened runtime and timestamp.

Testing

APP=build/RetroFind.app/Contents/MacOS/RetroFind
$APP -selftest                                   # ~80 automated checks: copy/metadata, conflicts, merge, undo, aliases, trash, labels, search, tabs, dual pane, batch rename, transfer queue, folder sizes, history, favorites
$APP -fresh -uitest -open=/some/folder           # walks the UI paths (four views, search, info, preferences, dialogs) and reports crashes
$APP -fresh -lang=en -demo -status -open=/tmp/mlf-demo -snap=/tmp/x.png -quit   # PNG of the window
# more switches: -view=icon|list|column|cover  -select=Name  -size=WxH  -realshot  -aqua  -xmode [-dual] [-tabs=a,b] [-right=path]  -show=prefs|info|viewopts|rename|queue
python3 Reference/compare.py /tmp/x.png 0 0 300 60 4   # pixel comparison against the reference screenshot

Documentation

docs/FUNKTIONSMATRIX.md maps every requirement of the specification to its implementation and test · docs/MESSKATALOG.md lists measured dimensions and sources · docs/ABWEICHUNGEN.md lists what is not (fully) possible on a current macOS · docs/ICONS-CREDITS.md documents the origin of all artwork.

Limitations

• Not available on today’s macOS (or only through system services): secure empty Trash, FTP writing and AFP, the 10.8 AirDrop protocol, Facebook/Flickr/Vimeo sharing, Folder Actions, the original AppleScript dictionary.
• The minimum window size (380 × 200) and some dimensions (column view) are working values – they were not measured on a real 10.8 installation. Pixel comparisons use screenshots only.
• Burning and volume encryption are implemented but untested without the hardware.
• Not available in the Mac App Store; distribution is GitHub only.

License & legal

• Code: GNU General Public License v3.0 (GPL-3.0). Copyright © 2026 Maik Klotz.
• Fan project: RetroFind is a non-commercial fan project, made out of respect and admiration for Apple and the design of OS X 10.8. It is free of charge, makes no claim to any Apple trademark, design or artwork, and is provided "as is" without warranty (GPL-3.0, sections 15–16). If you are a rights holder and have a concern, please open an issue – I will respond promptly and in good faith.
• No affiliation with Apple: RetroFind is an independent project, neither authorized nor endorsed by Apple. Lucida Grande is only referenced from the installed system.
• Assets: all icons (sidebar glyphs, folders, toolbar, traffic lights) are original drawings created for this project (Glyphs.swift) and covered by the GPL. No third-party or Apple artwork is bundled.
• App icon: Resources/AppIcon.icns is a user-supplied, AI-generated image (built with Reference/make_icon_from_image.py) and is not covered by the GPL; all rights reserved by the author. It resembles the former Apple Finder icon, so forks should ship their own – use the App icon setting (PNG 256 × 256) or Reference/make_icon.py (an original, GPL-covered alternative drawing). Icons you add yourself via Custom Icons stay in ~/Library/Application Support/RetroFind/CustomIcons on your machine and are not part of the app or this repository.