https://charleswiltgen.github.io/Axiom/ – Suite of skills, agents, and tools that make general SOTA models actually good at building and/or auditing iOS/macOS apps. Built for myself initially, I FOSS'd it once I determined how generally helpful it was. It's helped me learn a lot about doing sophisicated things with LLMs in a token-efficient way.

https://charleswiltgen.github.io/TagLib-Wasm/ – Also built for myself initially, I FOSS'd it because there was nothing like Mutagen for TypeScript/JavaScript runtimes. (I don't dislike Python, but think it's a bit of a mess.) This was my first serious project to leverage LLMs for coding.

https://pwascore.com/ – Built because I wanted to quantify how bad Safari was at PWAs. Learned that, objectively, Safari is as bad as PWAs as Firefox (which is to say, not terrible, and not to blame for why PWAs continue to be mostly-irrelevant).