The Bonsai CVS code management system is a computer program designed to help large programming projects productively manage CVS code archives. It was initially developed to fill the Mozilla project's need for good tools to allow multiple developers to edit its extremely large codebase.

Among other features, Bonsai allows complex queries to be performed, as well as near real-time updates of checkins to the CVS server.

Bonsai was founded by Terry Weissman. It was first written in TCL, then later ported to Perl. It still uses Perl, but runs off a MySQL database, and can be served using any Perl aware webserver, such as Apache.