Subversion, the new alternative to Concurrent Versions System (CVS) and the open source version control application that intends to replace CVS is covered in this addition to the In Action series. Providing all the benefits and features of CVS, but with many improvements, Subversion includes the ability to perform atomic check-ins, commit version numbers instead of file version numbers, and utilize better administration tools. Subversion users will also find information on the svnadmin and svnlook client interfaces, specific tools for system administrators and configuration managers, and details on advanced topics such as branching and triggers.