A macOS port of the classic XPenguins desktop toy. Cartoon penguins fall from the top of your screen, walk along the tops of windows, and shuffle around at the bottom of your display in front of the Dock.
Status: early port. Walking, falling, tumbling, and a reading idle action work; a skateboarder variant zips around faster. Several of the original states (climbing, floating, dying) are not yet implemented — see Roadmap.
- Requires: macOS 13 (Ventura) or later — enforced as the SwiftPM
deployment target in
Package.swift. - Tested on: macOS 15.7.2 (Sequoia), Apple Silicon. Older versions should work API-wise (we use only long-stable AppKit / CGWindow calls) but haven't been verified — reports welcome.
- Swift toolchain (Xcode or
xcode-select --install).
git clone https://github.com/MonkeyIsNull/MacPenguins
cd MacPenguins
./run_macpenguins.shThe script just runs swift run MacPenguins. The first run will
build (~1–2 seconds on Apple Silicon); subsequent runs are instant.
Hit Ctrl+C in the terminal to stop. There is no dock icon — it runs
as a background service drawing into a transparent overlay window
above the Dock.
- Penguins fall from the top of the screen and walk along the bottom
- Penguins land on the top edge of any open window and walk along it
- Penguins ride windows as you resize them, and fall off if you shrink a window past their feet or close it
- Tumbling: walking off a window's edge produces a cartwheel arc with the penguin's horizontal momentum carried into the fall
- Idle reading: normal penguins occasionally pause to read a book
- Multi-monitor (the screen-bottom ground is per-screen)
- A skateboarder variant (~3/8 of penguins) walks faster
These exist in the original XPenguins but aren't implemented yet:
- Climbers (scaling window sides / screen edges)
- Floaters (balloon-style upward drift)
- Death animations: explosion, splatted, squashed, zapped
- Angel ascent before respawn
- Digger idle action (skateboarder counterpart to the reader)
- Click-to-zap interaction
- Side-mounted Dock awareness
Sources/ Swift sources (build target)
main.swift Entry point
MacPenguinsService Update loop, spawning, lifecycle
SimplePenguin Per-penguin physics + state machine
SimpleCollision Window + ground surface tracking
SimpleWindowManager CGWindow polling
BasicRenderer NSWindow overlay + sprite rendering
sprites/ Pre-split walker frames + faller/tumbler
MacPenguins/Themes/ Original-style sprite sheets (incl. skateboarder)
The repo also has an MacPenguins.xcodeproj/ for opening in Xcode if
you prefer; the SwiftPM Package.swift is the canonical build target.
Rough order of attack for the remaining pieces:
- Climbers — when a walker hits a vertical obstacle, scale the window's side
- Death animations + angel respawn cycle (explosion / splatted / squashed / zapped → angel → faller)
- Floaters (balloon-style upward drift, used after head-bumping)
- Digger idle action (skateboarder pauses to dig — counterpart to the reader)
- Click-to-zap interaction
- Side-Dock and notch handling
Done so far: tumblers (walking off a window edge), reader idle action, and the skateboarder variant.
PRs welcome — bug fixes, items off the roadmap, new themes, or sprite improvements. Match the existing code style, keep changes focused, and verify visibly that your change works. No tests required; this is a desktop toy.
By submitting a PR you agree your contribution ships under GPL v2, matching the rest of the project.
Bug reports: please include your macOS version and a short repro.
New themes or sprites go under MacPenguins/Themes/<ThemeName>/ —
please credit any artwork you didn't draw yourself.
This is a port of Robin Hogan's XPenguins (1999–2001). All sprite
artwork is his, used under GPL v2. See CREDITS.md for
full attribution.
GNU General Public License v2 — see LICENSE.
This port is GPL v2 because the sprite assets are derivatives of
Robin Hogan's GPL v2 XPenguins artwork. The Swift code in Sources/
is original work and is also released under GPL v2 to keep the whole
package consistently licensed.