Why OpenBSD Developers Use CVS

The Concurrent Version System (CVS) maintained by Cyclic Software was selected for use by the OpenBSD project group. With cvs, seventy or so developers can update the source code (which is over 400MB, nearly 60000 files) that comprise the OS and its GUI. Countless OpenBSD users can download the OS sources via anonymous CVS, a procedure that is much more reliable than using Software Upgrade Protocol (sup) which certain other systems insist on using.

Since CVS interfaces with the Secure SHell (ssh) it can provide reliable user and host authentication. This fits in well with the OpenBSD project's goal of security.