https://github.com/pyjs/pyjs
Last updated June 14
> Things like Meteor and React address most of the issues and much more, such as live data and reactive UI.
They don't address one major issue - using a language of your choice.
(I don't use this project but I keep an eye on all 'Python in the browser' projects' and the minute one looks mature and sensible with some real-world takeup I'll be all over it)