It's definitely not in private beta, because I also just signed up. It's a bit confusing because you don't enter a password -- you just enter an email address.

It's definitely not in private beta, because I also just signed up. It's a bit confusing because you don't enter a password -- you just enter an email address. They then assume that you want to authenticate via github to use that email. Since Heroku's famous pivot, there have been a few companies that have built online web (and other) development collaborative development environments, including https://www.nitrous.io/ https://www.nitrous.io/, https://codio.com/ https://codio.com/, https://c9.io/ https://c9.io/, https://codenvy.com/ https://codenvy.com/, and https://koding.com/ https://koding.com/. There's also the more scientifically oriented environments like https://www.pythonanywhere.com/ https://www.pythonanywhere.com/, https://wakari.io/ https://wakari.io/, and https://cloud.sagemath.com https://cloud.sagemath.com. I don't think any have had breakout success yet. Of the above, at least https://c9.io/ https://c9.io/ and https://cloud.sagemath.com https://cloud.sagemath.com are open source. Disclaimer: I wrote https://cloud.sagemath.com https://cloud.sagemath.com, which is why I watch this space.