"To radically improve the web experience for users by enabling developers to use existing Java tools to build no-compromise AJAX for any modern browser."
Since our primary mission is to help users (as opposed to hoarding proprietary development tools), opening up GWT has always been a no-brainer -- we just had to decide when. Now that GWT has some serious adoption and a lively user community, open-sourcing is the obvious next step to help GWT evolve more quickly.
And we're committed to doing this the Right Way. All of our development will be done in the open, and we're going to be working directly from the GWT project on Google Code. We've created a charter document ("Making GWT Better") that describes the philosophical foundations of GWT as well as the nuts and bolts of compiling GWT yourself, contributing code, and participating in the new Google Web Toolkit Contributors group. We'll be discussing the GWT roadmap and all technical decisions publicly, we've republished the GWT web site documentation under a Creative Commons license, and, while we're at it, we'll be publishing our team meeting notes to the contributors group.
So, what's new in this 1.3 RC? Well, nothing, actually. The only thing that has intentionally changed since GWT 1.2 is the open source thing. However, since we did have to tweak a lot of source code and the GWT build scripts to make it easy for anyone to compile, we want to be conservative and call this a Release Candidate anyway. Once we hear enough success stories with the 1.3 RC, we'll call it 1.3 Final then get back to full-speed-ahead coding as we drive toward a nice big GWT 1.4.
So there you have it, GWT is open source!