Why I built this

I switched from Windows to a Mac about three years ago. The Dock has never stopped annoying me, and I think the reasons are objectively interesting, not just nostalgia:

1. You can't tell which windows are open. A dot under an icon means "running" — but if Chrome has 3 windows you see one dot. To switch to a specific window you right-click → pick from a list, or fall through Mission Control.
2. Minimized windows vanish. They collapse into a tiny thumbnail at the right edge of the Dock. With a busy Dock, they're effectively invisible. I've watched coworkers lose track of windows for hours.
3. No window titles. The Dock shows app icons. With four VS Code windows open, good luck telling them apart without hovering.
4. Notification badges are a red dot. Easy to miss. A flashing button is not.
5. No system tray. macOS has the menu bar, but it's at the top, space-constrained, and the notch ate half of it. The Windows taskbar — particularly the Win7 / pre-Win11 era — solved these in 1995 and the design has held up. I wanted that on macOS without giving up macOS itself. So: don't replace the Dock, run alongside it.

What it actually does

This isn't a CSS reskin of a Dock replacement. The window-management is real:

• Tracks every window on every screen via macOS Accessibility API; renders one button per window or per app (your choice).
• Hover preview of window contents (CGWindowListCreateImage at low frequency).
• Pin to taskbar, drag-to-reorder, persists across closes.
• Per-monitor independent taskbars — enable/disable on each display individually.
• Auto-hide with edge-trigger reveal.
• System tray with clock, volume slider (with output-device switcher), input-method indicator, custom app tray icons.
• Notification flash — orange button pulse when an app's badge or banner fires. Detected from the Notification Center DB + dock-tile badge changes.
• Start Menu per theme: Win98 single column, XP two-column with sidebar, Win7 with search, Win10 tiled grid with live-tile-style pinning.
• Power menu (Sleep / Restart / Shut Down / Lock / Log Off) with a theme-matching dialog for each — yes, including the XP "It is now safe to turn off your computer" energy.
• Auto-update via Sparkle.
• 6 languages (EN, 简中, 繁中, 日本語, 한국어, FR).

The themes are the point

Each theme is a from-scratch render: button bevels, gradient stops, font hinting, the corner radii on Aero glass, the exact pixel offset of the Win98 raised-edge. I rebuilt the assets rather than ripping bitmaps because I wanted everything to scale cleanly from 50% to 200% (a hard constraint on Retina + multi-DPI setups).
Win10 uses NSVisualEffectView for Acrylic. Win7 uses a layered blur stack to fake Aero on macOS (which doesn't expose the same compositor primitives). Win98 / XP are plain Core Graphics — no blur, just bevels and gradients, which oddly turned out to be the most fun to draw.

Honest comparison vs uBar

uBar has owned this niche on macOS for a decade. Worth being upfront:

If you want a modern Dock alternative, uBar is great. If you specifically want the Windows taskbar you grew up with, that's where RetroWin fits.

Things I underestimated

A few war stories for any Mac dev considering this kind of project:

• Accessibility permission and code-signing. I'm not in the Apple Developer Program, so every release ships with a different ad-hoc signature, which means macOS revokes Accessibility every update. There's a documented FAQ workaround (remove + re-add in Privacy settings), but the right fix is buying into the $99/yr program — on the roadmap.
• Window event polling. AXObserver gives you create/destroy events for windows, but not reliably across all apps. I ended up with a 1Hz reconcile loop on top of event-driven updates. CPU stays under 0.5% on an M2.
• Notification detection. There's no public API. I read the Notification Center SQLite (~/Library/Group Containers/group.com.apple.usernoted/db2/db) and watch dock-tile badge attributes via AX. Brittle but it works.
• Multi-monitor + Spaces + fullscreen. Each fullscreen window lives in its own Space. Drawing the taskbar on top requires the right NSWindow.collectionBehavior flags or it just disappears when you swipe between Spaces. Took an embarrassing amount of trial and error.
• Per-theme everything. It's tempting to share Start Menu code. Don't. The four eras have genuinely different interaction models — search is a first-class verb in Win7+, not in Win98 — and trying to abstract them produced worse code than four parallel implementations. ## What it's not
• Not a Dock replacement. Run them together, or hide the Dock yourself in System Settings.
• Not signed/notarized yet. Gatekeeper will warn on first launch — Open Anyway, or xattr -cr /Applications/RetroWin.app.
• Not open source (yet). The release repo (issues + downloads) is public; the source isn't. Happy to discuss if there's interest.
• Not a Windows compatibility layer. It's a taskbar. Your apps are still macOS apps. ## Try it Download the latest DMG from the GitHub releases page, drag to Applications, grant Accessibility, pick a theme. I'd genuinely love feedback on:
• Theme accuracy — if you spot something un-period-correct, file an issue with a screenshot. I will fix it.
• Edge cases on weird monitor setups (eGPU, mixed Retina/non-Retina, vertical screens).
• Whether you'd want a Win11 theme. (I keep going back and forth on this. Win11's taskbar is the most controversial of the bunch.) Thanks for reading.