> Twisted, Gevent, Celluloid, EventMachine all did too. The problem is, they've never reached critical mass, and their respective languages refused to bless the

> Twisted, Gevent, Celluloid, EventMachine all did too. The problem is, they've never reached critical mass, and their respective languages refused to bless them as "official." At least in the case of Twisted, it probably didn't help that for a long time it was GPL licensed with all community contributions requiring copyright assignment to the lead developer.