A "next-generation" distributed version control tool. Free, written in Python, and with an interface similar to CVS and Subversion.

A decentralized version control system based on secure hashes and cryptographic signatures. (Open Source)

Utility based on the author's "theory of patches" in which they are likened to operators in quantum mechanics. Additionally, every copy of the source is a full repository. Written in Haskell and released under the GNU GPL.

A client/server configuration management system. The server supports UNIX and Windows NT. The client supports most platforms via command-line, GUI and Web browser-based interfaces. (commercial) (Perforce Software)

Software configuration management tools and related utilities, as well as information about SCM concepts and methodologies in the file sharing area.

The Project Revision Control System is a front end to a set of tools that provide a way to deal with sets of files and directories as an entity, preserving coherent versions of the entire set. (GPL) (Josh MacDonald)

Comes in Pro and Basic versions (Pro supports repository hierarchy, rollback, event triggers). Distributed system, with a repository for each developer. Unix/Linux, MacOSX on PPC and Windows 98 and up. Commercial.

Key functions of StarTeam include requirements management, change management, defect tracking, file versioning, threaded discussion, and project task management. (commercial) (Borland)

Offers commercial Subversion, CVS, and Wiki Hosting, as well as bug tracking tools and informs about its products.

Vault is a source control tool designed to be a compelling replacement for Visual SourceSafe.