Meanwhile in an alternate universe where the TBGs runs on Simple Machine Forums...
This is a collection of SMF themes used to mimic the styles on the TBGs.
You may have realized that this branch is just the default Curve2 theme. That's because this is the base template for the other branches inheriting from this branch. Each branch is a different style, and a branch could inherit another branch (which could be useful if you have two same style with only the colors changed)
This chart may help with the branching model we're using here.
Now, is this how you should develop software on a Git enviroment? I... don't recommend it. But hey, this is a theme, not a program. There's no "features" to add, so might as well make all changes hotfixes.