Git is a free & open source, distributed version control system designed to handle everything from small to very large projects with speed and efficiency.

Every Git clone is a full-fledged repository with complete history and full revision tracking capabilities, not dependent on network access or a central server. Branching and merging are fast and easy to do.

Git is used for version control of files, much like tools such as Mercurial, Bazaar, Subversion, CVS, Perforce, and Visual SourceSafe.

Git在苹果系统上非常流行。

Mercurial : http://www.selenic.com/mercurial/wiki/

http://mercurial.selenic.com/

A fast, lightweight Source Control Management system designed for efficient handling of very large distributed projects.

Bazaar : http://bazaar-vcs.org/

Bazaar is a distributed version control system that Just Works. While other systems require you to adapt to their model of working, Bazaar adapts to the way you want to work, and you can try it out in five minutes.

MySQL, Mailman, Launchpad, and the Linux Foundation are among the many projects and organizations using Bazaar.

Bazaar runs on Windows, GNU/Linux, UNIX and Mac OS, and requires only Python 2.4. If you can run Python, you can run Bazaar! It is an official GNU project, licensed under the GPLv2 or later, at your option.

Perforce  : http://www.perforce.com/perforce/products.html

The Perforce Software Configuration Management System features comprehensive SCM capabilities built around a scalable client/server architecture. Users can access the Perforce Server through a range of Perforce client software. Perforce can be deployed quickly and easily, and requires minimal administration even for large or distributed sites

参考：

http://en.wikipedia.org/wiki/Distributed_revision_control

为什么我们要放弃Subversion : http://www.infoq.com/cn/articles/thoughtworks-practice-partiv