AccuRev Transaction-based, client/server via TCP/IP. Server runs on Unix/Linux, NT/2000/XP. Client also runs on Windows 95/98/Me. Supports server- and client-side triggers. (commercial) (AccuRev, Inc)
http://www.accurev.com/
BitKeeper 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. Traditional commercial license available, als
http://www.bitkeeper.com/
ChangeMan "Enterprise Change Management": Family of tools for mainframes to distributed systems to web apps. Formerly eChangeMan; Diamond CM; VCS-UX/3000. Support for various platforms, depending on the tool. (commercial) (SERENA Software Inc)
http://www.serena.com/product/cm_prod.html
CM+ Offers configuration management with data management and process control. Also covers version control, build and release management, change control, and problem and activity tracking. (commercial) (Neuma Technology Inc.)
http://www.neuma.com/
CMZ A file system based source code management and version control system. Unix/Linux, VMS, WinNT. (non-commercial) (CodeME S.A.R.L.)
http://wwwinfo.cern.ch/cmz/
Code Co-op Works on a LAN but allows synchronization over email. Distributed, transaction-based, server-less. Windows 95 and up, "Linux version to come". (commercial) (Reliable Software)
http://www.relisoft.com/co_op/
DocStudio shwow!DocStudio is a development tool that allows developers to spec software projects before and during development. It also has full source and version control built in and can be used for just this purpose. Web-based system for Internet Explorer
http://www.shwow.com/
OpenCM OpenCM is a configuration managment system designed for high-integrity operation. It supports cryptographic authentication, end-to-end integrity controls, and file-level ACLs. (open-source)
http://opencm.org/
Perforce A client/server configuration management system. The server supports UNIX and Windows NT. The client supports more than 50 platforms via command-line, GUI and Web browser-based interfaces. (commercial) (Perforce Software)
http://www.perforce.com/
PRCS 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)
http://prcs.sourceforge.net/