TopGit is described as 'Aims to make handling of large amount of interdependent topic branches easier. In fact, it is designed especially for the case when you maintain a queue of third-party patches on top of another (perhaps Git-controlled) project and want to easily organize, maintain and' and is a Version Control system in the development category. There are 2 alternatives to TopGit for Mac, Linux, BSD and Windows. The best TopGit alternative is pbranch, which is both free and Open Source.
Patch branches (pbranch) is a way to develop a series of patches for submission into a main Mercurial repository. It is based on topic branches, one per patch, and is thus highly suitable for collaborative and/or long-term patch development and maintenance.
pbranch is the most popular Windows, Mac & Linux alternative to TopGit.
pbranch is the most popular Open Source & free alternative to TopGit.
git-assembler can perform automatic merge and rebase operations following a simple declarative script. Like “make”, for branches.