BZFlag 2.0.9 is an unreleased development branch of BZFlag. It is an extension of the source code released with version BZFlag 2.0.8 of the game. It contains minor bug fixes and patches mostly relating to BZFS and the BZFS API. This code base is only available from the SVN repository. That SVN link tells how to get an SVN client for your system, but doesn't mention that the correct branch and command to download is:
There are currently no plans to release a 2.0.10 version of BZFlag.
Development on new features has proceeded in BZFlag 2.2