Brython, Transcrypt, RapydScript, Skulpt and PyPyJS provide various tradeoffs between compatibility and speed.

Nim does server and client as well (compile down to C or JS serverside, JS clientside), and has Python inspired syntax and standard library.

GWT gives you that for Java; Emscripten and recently WASM gives it to you with basically anything gcc can compile and then some.

There is no need to wait.