Releasing is hard
You might have noticed some delay in releasing Sunbird 0.3a1. There were some problems on the road, like lack of time, the tree being broken at the wrong moment, cvs acting weird, last-minute bugs etc.
But it's done now. Builds are up at http://ftp.mozilla.org/pub/mozilla.org/calendar/sunbird/releases/0.3a1/, there are release notes and there even is a cvs tag (SUNBIRD_0_3a1_RELEASE)
Of course this is still an alpha build. There are problems, lots of them. We know about that. But we also have more changes ahead, and didn't want to delay the release any further. Please take that into account when testing and using 0.3a1.
The biggest change since 0.2 is a complete rewrite of the backend. It is now possible to plug in new calendar providers (code that stores the calendar data in some file or database). We already have an ICS provider, a SQLite provider, and the beginnings of a CalDAV provider, and we expect others will come with time (let us know if you want to implement one). Writing a new backend isn't easy, so it took some time. But we think it was worth it. It gives the possibilty to do real cool things.
The upcoming changes include a rewrite of the calendar views, improved performance, backend improvements and much more. Stay tuned!