I'd like to use Draw.io in real time collaboration with a colleague—the About page says it can be done—, but I can't see any options. How can I do it?
On the Chrome Web Store, there are 2 draw.io entries, the standard non-RT version and the RT version, you need the later version for sharing. The entries are identical, apart from which sub domain they route you to, www or drive.
The reason we didn't make it default for Drive users was we wanted to monitor how stable is was. It's actually been more stable than the non-RT storage lately, so it might well be set to default in 2014.
You can use the drive.draw.io sub-domain and stay on it though, that won't be removed.