That JavaScript/TypeScript runtime idea I mentioned has mutated a bit.

Once I actually thought about it, writing another Node.js/Deno/Bun-shaped runtime didn't seem especially useful; there are enough of those already. What I actually want to try is an ahead-of-time JavaScript/TypeScript compiler in roughly the SBCL/Chez Scheme tradition: native code, with a generic implementation always available and specialized versions picked by cheap runtime guards. A failed guard just falls through to code that's already compiled, rather than needing an interpreter or a deopt path. There are probably adjacent projects doing pieces of this, so I won't claim the territory is empty, but I haven't seen this exact shape applied to JavaScript/TypeScript. I've codenamed it Oseo (鼯鼠; flying squirrel in Sino-Korean).

It's still just a compiler experiment, not something I'd call presentable yet, so the repo stays closed for now. Once it works well enough, the first thing I want to try is switching the Fedify CLI, currently built with deno compile, over to Oseo and seeing what breaks. Fedify is the ActivityPub server framework I also maintain, so it should make a reasonably unforgiving first customer. I'll keep picking at Oseo for the next few months and post again when something interesting starts working.