Swiftweasel project is an optimized build of the Mozilla Firefox web browser for Linux.
The builds will also fall into 3 versions.
1. Releases - Releases are based on versions of Firefox released by Mozilla. The current release is 22.214.171.124.
2. Branch - The branch is where minor fixes and security enhancements are worked on. The current branch is 1.8.1 (126.96.36.199 pre) witch will become the 188.8.131.52 version upon release. The code in the branch while not quite ready for release has had more testing done to it and is much more stable than the trunk.
3. Trunk - This is where development for Firefox 3 is being done. Its development name is Minefield to give you an idea of how stable it is. It is on the cutting edge and should be expected to have bugs.
At present the available Swiftweasel versions are 184.108.40.206 (Release) and 3.0a5 (Trunk). A release of the new 220.127.116.11pre (Branch) should be avilable in a few days.