WEBRCS is a simple perl CGI (plus some Apache mod_rewrite lines) that transparently exports the MainLine of a CVS repository as a website. It has served The Herd Of Kittens since early 1998, and has served a handful of ORG and COM websites since then.
Note that this is different from CVSWEB and WEBCVS in that it is very specifically not intended as an alternate interface to CVS, but instead uses CVS as a tool to manage a static website.
In spite of the crude initial design (perl CGI that execs "co" every time) it served the needs of a several project sites off of a single 486 running Debian. Thanks to SourceForge, it is now undergoing performance work and porting.
License terms come from The zlib/libpng License (found on the OpenSource site) rather than the GPL, mostly because it bothers me to use a license larger and more complex than the code itself.