Compile Python into JS
empythoned is maintained by repl.it: https://github.com/replit/empythoned
Transcrypt is a two-way Python-JS transpiler. New, not sure how active.
Skuplt is a JS implementation of Python 2.x. Seams active.
RapydScript has a syntax that is similar to Python and compiles into JS.
Brython is a Python 3 implementation running in the browser.
PyPyJS is a JIT compiler for Python built in JS
Batavia is a Python 3 virtual machine implementation in JS.