If you want to control the past, especially if you come from older VCS's like SCCS or CVS and moved to GIT, this module is your friend. A better name might have been Git::Stitch, but then again, what's in a name.
Branches are complex, and merging old (misplaced) branches from old repositories into one new comprehensive repository is quite difficult, even if you know the commands of the VCS at hand.
This module makes hard things relatively easy, but be sure that you envision your target before you go stitching/merging/joining.
Do not miss the script/ folder that is in this distribution. For me that is way more valuable then the module itself. Thanks BooK!