Twgit is a free and open source assisting tools for managing features, hotfixes and releases on Git repositories. It provides simple, high-level commands to adopt the branching model describes in our documentation. Supported OS: Debian/Ubuntu Linux, Mac OS X 10.8 (Mountain Lion) or lower.
twgit feature|release|demo archive [filename]
Some examples from http://stackoverflow.com/a/163769/1813519 :
Manual: http://git-scm.com/docs/git-archive