Things that have caught my eye but which I haven't had time yet to explore. (I often dump links here when I decide it's time to close a bunch of tabs.)
Manyfold: Fediverse 3D print sharing, similar to Printables or Thingiverse.
Cooklang: A project that seems to have goals and an approach similar to food bot.
MunalOS: OS in Rust running WASM applications and using WASM for sandboxing. No memory mapping, very simple. Interesting direction, one which I've wanted to see explored for some time now.
Future of Coding: "Future of Coding is an online community with a welcoming, cooperative, and revolutionary spirit. We are unified in the belief that the computer is tragically less humane than it could be."
Nuklear UI: C-based, single-file UI toolkit. Uses immediate mode, has zero dependencies, and written in C89 (which should mean it'll build even under the compilers available for old OSes like Windows 3.11.)