I haven't yet talked about the API for 1999.io. It's inspired by Facebook's JavaScript API, which is excellent, with an important additional feature, storage. Without that you can't build real apps. 

This API does what the XML-RPC interface did for Manila, WordPress and Blogger in the 1999 version of the blogosphere. This time around it's JSON over HTTP. The browser-based editor for 1999.io is implemented on top of this API, which is open to any other developer to use. 

I'll be demoing this first on the 1999-server list hopefully in the next few days.