Cil is an easy-to-use command-line driven distributed issue tracker. Using Git as it's storage backend, the power of a distributed version control system can be harnessed to enhance and provide powerful features. Cil saves the issues, comments, and attachments locally in plain-text for ease of use and easy accessibility.
gitolite is an access control layer on top of git. It allows you to setup git hosting on a central server, and have multiple "virtual" users (i.e., not "Unix" users) access multiple git repositories, with fine grained access control (read control at the repo level granularity, write control at branch/tag/file/dir level). It has several other features, comprehensive documentation, does not require root permissions, and does not depend on anything except git, Perl 5.8 or later, and any POSIX shell.
owl2vcs is a set of tools designed to facilitate version control of OWL 2 ontologies using version control systems. It contains a commandline diff tool for OWL 2 ontologies integrated with Git and Mercurial. It detects axioms additions and removals, imports' additions and removals, ontology annotations' additions and removals, prefix additions, removals, modifications, and renames, ontology IRI and version IRI changes, and ontology format changes. It supports RDF/XML, OWL/XML, OWL Functional Syntax, Manchester OWL Syntax, and Turtle. It provides a changeset serializer and parser, two formats of changes, compact (like OWL Functional Syntax) and indented (the same, but more readable, using indents instead of parentheses), and four formats of IRIs: Simple, QName, Full, and Label.
git-flow Python Edition is a a pure Python implementation of git-flow. All sub-commands share a common back-end to ensure features behave the same, whatever branch-type they are working on. New workflow behavior can also be added easily by simply sub-classing existing ones. It also includes a comprehensive unit test suite, decent man pages, and HTML docs.