The latest snapshot build (usually uploaded in sync with this website) can be downloaded directly from here. Get this one only if you are a developer or you absolutely need a feature/fix added before the latest release (see changes for the full change log).
You can also obtain the source from the SourceForge CVS Server, see Source Repository.
The "bin" versions include the following:
The "src" versions includes the complete source code to the tag library, the various example pages, and the documentation.