rStat.us is an OStatus-based microblogging service built by Steve Klabnik and others using Ruby, Sinatra and MongoDB. Because it uses OStatus, it's compatible with Identi.ca and StatusNet microblogs. In order to follow someone from Identi.ca, just paste the ATOM feed from their profile into rStat.us. Theoretically this should work both ways, but I was unable to subscribe to my own rStat.us account from Identi.ca account.

Klabnik and some friends started it after Twitter changed its terms of service and began discouraging developers to start new Twitter clients.

Writing at The Changelog, Klabnik explained the origin of the project.

If you didn't hear, a week ago Friday Twitter changed their terms of service. This got a lot of people upset, including me. My friends and I started thinking about it, and the real problem is this: any software that's owned by one entity, corporate or not, is open to the possibility of being abused.

So we decided to fix it. Ten days later, here we are: http://rstat.us/ is born.

rStat.us is an extremely simple microblog. You can post a status, read replies, follow people and read their updates. That's about it. "We pride ourselves on saying 'no' to lots of features," the site says.

The code is available on  Github, so you can start your own rStat.us server if you want to.

This project is very similar to StatusNet, the microblogging engine that powers Identi.ca. But rStat.us is written in Ruby instead of PHP, which might attract more developers.

It's one of many projects addressing the problem of centralization and data portability on the Web. Others include Diaspora, Couchappspora,  Apache CouchDB and Unhosted. For more information on this movement, check out our interviews with some of the developers of these projects:

Klabnik also maintains the cross-platform Ruby GUI toolkit Shoes and HacketyHack, the interactive Ruby tutorial we covered here. Both of these projects were created by why the lucky stiff.