cvs-fast-export analyzes a collection of RCS files in a CVS repository (or outside of one) and, when possible, emits an equivalent history in the form of a fast-import stream. Not all possible histories can be rendered this way, and the program tries to emit useful warnings when it can't. The program can also produce a visualization of the resulting commit DAG in the DOT format handled by the graphviz suite.
gitg targets cases where it is useful to provide a graphical representation of Git data or actions. The history view is a good example, where graphical representation helps to get an overview of the repository. gitg does not aim to be an advanced tool that allows access to every feature of Git through a graphical interface. However, it will try to incorporate common actions that might require multiple actions on the command line (like staging, unstaging, reverting, and committing).
deltasql is a tool to synchronize databases with source code, which helps to keep database evolution under control. While developing mid-sized or big applications, developers make changes to the data model that go along with changes to the source code. From time to time, branches of source code are done to stabilize the code that will go to production. A sort of data model branch is also needed. deltasql provides a simple way to collect all scripts that change the data model and means to handle data model branches. The deltasql server runs on Apache and is backed by MySQL.
vss2svn is a Perl script (vss2svn.pl) and accompanying C program (ssphys.exe) to migrate revision history from a Microsoft Visual SourceSafe (VSS) database to a Subversion repository. This combination of programs was designed by reverse-engineering the backend database structure of Microsoft's VSS repository. In doing so, the authors have made progress towards overcoming the inability of even Microsoft's own API to properly recover deep history from VSS. This also means that you don't actually need a copy of VSS or its libraries to convert your repository.
Subversion Labels is a set of scripts and server-side hook programs that allow people to give Subversion revision numbers more meaningful aliases (such as release-1.1.2beta), and use them instead of remembering revision numbers. It does not require modification/recompilation of the Subversion server/client code, and is aimed at people who dislike Subversion's tags-are-branches approach.