The WiFi Radar GIT repository is located on TuxFamily and mirrored at repo.or.cz (gitweb). It contains the history of WiFi Radar development since 2004-12-22. There is one branch per release series. The current list of branches is v1.9.x, v2.0.x, and master for the old, stable, and development series, respectively.
To get a local copy to work with:
$ git clone git://git.tuxfamily.org/gitroot/wifiradar/wifiradar.git
To check what branches you have copied locally, use:
$ git branch
You should see:
To create a new branch and change to it:
$ git checkout -b fix-we_mode
gitk is your friend. gitk is a graphical client that simplifies some GIT operations, but mainly provides a visual graph of your branches and how they are related.