Source Code Management
Fiji's development relies heavily on Git. The principal Fiji project is a Git supermodule, which includes submodules -- projects in their own right. These submodules do not have to be checked out, but can be left empty, if you are not interested in the development of that particular project.
Some of Fiji's submodules are imported from third parties; most of them have their source code in Subversion repositories, which are mirrored via git-svn. The mirrors are updated by a cron job on Pacific.
Some useful documentation, in particular for Fiji: