Real-time GPU-rendered Mandelbrot and Julia set screensaver for macOS
Download Latest Release → Unzip → Double-click → Done
The Problem: macOS screensavers are boring. The built-in options are static images or basic animations. Third-party fractal viewers are either outdated, slow, or cost money.
The Solution: A free, GPU-accelerated Mandelbrot/Julia set screensaver that renders beautiful deep zooms at 60fps using Apple's Metal framework.
| Feature | What It Does |
|---|---|
| 60fps Metal Rendering | Buttery smooth zooms powered by your Mac's GPU |
| 24 Color Palettes | From classic Ultra Fractal to Neon, Vapor, and Candy |
| Julia Set Mode | Alternates between Mandelbrot and mesmerizing Julia sets |
| P3 Wide Gamut | Vivid colors that pop on modern Mac displays |
| 3D Lighting | Optional Blinn-Phong shading with specular highlights |
| Zero Config | Works beautifully out of the box, customize if you want |
1. Download MandelbrotSaver.saver.zip
2. Unzip
3. Double-click MandelbrotSaver.saver
4. Click "Install"
5. Open System Settings → Screen Saver → Select "Mandelbrot"
That's it. Your Mac now has a continuously zooming fractal screensaver.
| Feature | Mandelbrot Saver | Electric Sheep | Fliqlo | Built-in macOS |
|---|---|---|---|---|
| GPU Accelerated | Yes (Metal) | No (CPU) | No | Partial |
| Continuous Zoom | Yes (cycles through locations) | No | No | No |
| Customizable | Yes (24 palettes, 4 shading modes) | Limited | No | Limited |
| Julia Sets | Yes | No | No | No |
| Free | Yes | Yes | Yes | Yes |
| Works Offline | Yes | No (needs network) | Yes | Yes |
| Wide Gamut (P3) | Yes | No | No | Partial |
Best for: Anyone who wants a beautiful, mesmerizing screensaver that showcases their Mac's GPU.
Not ideal for: Users who prefer static images or clock-based screensavers.
No Xcode or developer tools required.
- Download
MandelbrotSaver.saver.zipfrom Releases - Unzip the file
- Double-click
MandelbrotSaver.saver - Choose "Install for this user only" (or "Install for all users" if you have admin rights)
- Open System Settings → Screen Saver and select Mandelbrot
Requires Xcode with Metal compiler.
git clone https://github.com/ProofOfReach/MandelbrotSaver.git
cd MandelbrotSaver
./build.sh --installBuild options:
./build.sh # Build only (creates MandelbrotSaver.saver/)
./build.sh --install # Build and install to ~/Library/Screen Savers/Click Options in System Settings → Screen Saver to customize:
| Setting | Options | Default |
|---|---|---|
| Zoom Speed | Slow ← → Fast slider | Medium |
| Palette | 9 color schemes (6 standard + 3 P3 wide gamut) | Ultra Fractal |
| Auto-cycle Palettes | On/Off | On |
| Shading Mode | Flat, 3D Blinn-Phong, Angle-based, Stripe | Flat |
| Julia Set Mode | On/Off (shows Julia sets every 4th zoom) | Off |
Standard:
- Ultra Fractal (classic blue-gold)
- Fire (red-orange-yellow)
- Ocean (deep blues and teals)
- Electric (cyan-magenta)
- Sunset (warm oranges and purples)
- Glacial (icy blues and whites)
P3 Wide Gamut (for displays that support it):
- P3 Electric
- P3 Fire
- P3 Ocean
| Mode | Description |
|---|---|
| Flat | Classic smooth coloring based on escape iterations |
| 3D Blinn-Phong | Simulated 3D surface with highlights and shadows |
| Angle-based | Colors derived from escape angle for psychedelic effects |
| Stripe | Orbital trap coloring with stripe patterns |
┌─────────────────────────────────────────────────────────────────┐
│ macOS ScreenSaver Framework │
│ (ScreenSaverView) │
└─────────────────────────────────────────────────────────────────┘
│
▼
┌─────────────────────────────────────────────────────────────────┐
│ MandelbrotView.swift │
│ - Animation state machine (zoom → fade out → fade in) │
│ - MTKViewDelegate for P3 rendering │
│ - Curated zoom target locations │
└─────────────────────────────────────────────────────────────────┘
│
┌───────────────────┼───────────────────┐
▼ ▼ ▼
┌──────────────────┐ ┌──────────────────┐ ┌──────────────────┐
│ Mandelbrot.metal │ │ Preferences.swift│ │ ConfigureSheet │
│ - GPU compute │ │ - User settings │ │ - Options UI │
│ - 24 palettes │ │ - Persistence │ │ - No XIB needed │
│ - Julia mode │ └──────────────────┘ └──────────────────┘
│ - 4 shading modes│
│ - dd_real math │
└──────────────────┘
Key Design Decisions:
- Metal Compute Shaders - Each pixel computed independently on GPU for maximum parallelism
- MTKView for P3 - Uses
rgba16Floatpixel format anddisplayP3colorspace - Double-Float Precision - Custom
dd_realarithmetic for deep zooms without pixelation - Programmatic UI - No XIB/NIB files, all configuration UI built in code
Cause: Installation didn't complete or macOS security blocked it.
Solution:
# Check if installed
ls ~/Library/Screen\ Savers/
# Reinstall
./build.sh --installOr manually copy MandelbrotSaver.saver to ~/Library/Screen Savers/.
Cause: GPU initialization can take a moment on first launch.
Solution: Wait 2-3 seconds. If still black, try selecting a different screensaver and then re-selecting Mandelbrot.
Cause: P3 palette selected on non-P3 display.
Solution: In Options, choose a standard palette (Ultra Fractal, Fire, Ocean, Electric, Sunset, or Glacial).
Cause: System Settings quirk when screensaver first installed.
Solution: Close and reopen System Settings, or log out and back in.
- Search existing issues
- Open a new issue with:
- macOS version
- Mac model (Intel or Apple Silicon)
- Screenshot of the problem
- No manual navigation - This is a screensaver, not an interactive explorer. It auto-zooms to curated beautiful locations.
- No arbitrary deep zoom - Limited to ~10^5 zoom depth to maintain visual quality (deeper causes pixelation).
- No Buddhabrot/Burning Ship - Only standard Mandelbrot and Julia sets.
- No Windows/Linux - macOS only (uses Metal and ScreenSaver framework).
| Issue | Workaround | Status |
|---|---|---|
| First frame may stutter | Wait for GPU warmup | By design |
| Hot corners conflict | Disable hot corners or adjust trigger delay | macOS behavior |
Named after Benoit Mandelbrot, the mathematician who studied and popularized fractals. The Mandelbrot set is the most famous fractal, defined by the simple equation z = z² + c.
Yes. The code is open source and does exactly what it claims: render fractals. It doesn't access the network, read your files, or do anything except draw pretty pictures.
Like any GPU-intensive task, it uses more power than a static screensaver. On laptops, macOS typically prevents the screensaver from running on battery unless you configure it otherwise.
Not currently. The screensaver cycles through 8 curated beautiful locations. Adding custom locations would require modifying the source code.
Quality over quantity. Each location was hand-picked to look beautiful at all zoom levels without hitting precision limits. Adding arbitrary locations risks ugly artifacts.
The build script currently targets Apple Silicon (arm64). For Intel Macs, modify build.sh to use -target x86_64-apple-macosx12.0 instead.
Pull requests welcome! Areas of interest:
- Universal binary support (Intel + Apple Silicon)
- Additional palettes
- New shading modes
- Performance optimizations
MIT License - Free to use, modify, and distribute.
See LICENSE for details.