Screen Savers

I recently wrote three small screen savers for macOS. That was a ton of fun. There is something therapeutic about it. I am making them all available as open source. Let me know what you think.

Sad mac

This one is an ode to the classic Mac. The Sad Mac would show up if it’s internal hardware test failed. Like when you had a bad RAM chip.

Sad Mac Screen Saver

Code-wise it is a very basic screen saver actually. Just drop sprites on the floor and let them pile up. The thing that took some time was to get the physics parameters right to make it feel natural.


The Sliding Puzzle from After Dark was probably my favorite back in the day. It just worked so well and smooth. And I think I specially loved the ones that messed with your actual screen.

Puzzle Screen Saver

My re-implementation simply chops up a screenshot and then turns the pieces into SpriteKit nodes. Those can then easily be moved around. SpriteKit is pretty amazing. I have found it very simple to turn ideas into working prototypes.


This one shows the new Mozilla logo and drops two sizes of Firefox (Focus/Nightly) icons on it. There is lots of bouncing and I spin the logo around if too many pile up.

Mozilla Screen Saver

Since the logo is not a simple rectangular bounding box, I had to create an outline for the collission detection. I used a nice little web based tool that let me draw the path on top of the image and generated Objective-C code that.

Most of my work is open source. You can see all projects at - feel free to leave a bug report or open a feature request.