Seeing Bun/Node/Deno support reminds me of a question: are there any good resources on writing JS that works in all 3 and the browser? For example if I wanted to write a simple filesystem API that would work the same across bunodeno?
Best bet is to use the Node fs package and rely on the deno/bun compatibility layer.
More generally, Deno pushes for Web Platform APIs, and as more are proposed and implemented the runtime-specific APIs will become fewer and fewer.