Apps similar to Pyjs include JavaScript, which is free and open source. Other options are ReScript, Brython, Transcrypt and RapydScript. In total there are seven Programming Languages like Pyjs for Windows, Linux, Mac, the web and Chrome OS.
JavaScript (sometimes shortened to JS) is a lightweight, interpreted, object-oriented language with first-class functions, most known as the scripting language for Web pages, but also used in many non-browser environments.
United States
ReScript is a robustly typed language that compiles to efficient and human-readable JavaScript. It comes with a lightning fast compiler toolchain that scales to any codebase size.
Brython's goal is to replace Javascript with Python, as the scripting language for web browsers.
Transcrypt is a tool to precompile a fairly extensive subset of Python into compact, readable Javascript.
Netherlands
EU
RapydScript is a pre-compiler for JavaScript, similar to CoffeeScript, but with cleaner, more readable syntax. The syntax is very similar to Python, but allows JavaScript as well. It's not another Python-in-a-browser clone, it's actually JavaScript with more Pythonic...
Russia
Real-Time JavaScript Tool is a portable tool that allows JavaScript codes to be executed in Real-Time!
Python-like syntax interpreter implemented with javascript that runs entirely in the web browser and/or in the NodeJS environment.
United Kingdom