chapotraphouse

I like Guile with its compiler tower. You can use multiple languages on the same VM, even using libraries from one language on another, which is fucking cool. The core language for Guile is Scheme, and it supports standards from R4RS-R7RS, along with plenty of built-in SRFIs, some implemented out-of-tree and many of its own Guile-specific extensions.

For the compiler tower, so far we've got the aforementioned ballin' Scheme implementation, Emacs Lisp, an unfinished JavaScript implementation that doesn't even fully implement ES3, Brainfuck, Python, wonky Lua, and Guile-specific Clojure. Hopefully there's more to come and there's some I missed.

While the main purpose for the compiler tower is to lower a language into the IR (Tree-IL) (although you can lower a language into another language too, which then itself can be lowered into IR), which gets lowered to more verbose IR (CPS), then bytecode - we can also raise IR through decompilation. For example, Guile-JavaScript compiles Scheme to IR, then decompiles the IR and raises it to JavaScript.

Then there's also Guile Hoot, which I believe lowers the IR into WASM. In theory, when its complete, the above languages could work with Hoot and he compiled to Hoot, but I'm not entirely sure on this.