Many other third-party packages are available for CVS. Following are pointers to some of these.
CVSUp is an efficient generic mirroring tool with special built-in support for mirroring CVS repositories. The FreeBSD operating system uses it to distribute changes from their master repository, so users can keep up to date conveniently.
For more information on CVSUp in general, check out http://www.polstra.com/projects/freeware/CVSup/.
For its use in FreeBSD in particular, see http://www.freebsd.org/handbook/synching.html#CVSUP.
CVSWeb provides a Web interface to browsing CVS repositories. A more accurate name might be "RCSWeb", because what it actually does is allow you to browse revisions directly in a repository, viewing log messages and diffs. Although I've never found it to be a particularly compelling interface myself, I have to admit that it is intuitive enough and a lot of sites use it.
Although the software was originally written by Bill Fenner, the version most actively under development right now seems to be Henner Zeller's, at http://linux.fh-heilbronn.de/~zeller/cgi/cvsweb.cgi/.
You may also want to visit Fenner's original site at http://www.freebsd.org/~fenner/cvsweb/ and possibly this summary of the CVSWeb scene at http://www.cvshome.org/dev/addoncvsweb.html.
Finally, if you'd like to see CVSWeb in action, a good example can be browsed at http://sourceware.cygnus.com/cgi-bin/cvsweb.cgi/.
As mentioned in Repository Administration, a number of third-party tools are shipped with CVS and are collected in the contrib/ directory. Although I'm not aware of any formal rule for determining which tools are distributed with CVS, an effort may be in process to gather most of the widely used third-party tools and put them in contrib/ so people know where to find them. Until that happens, the best way to find such tools is to look in contrib/, look at various CVS Web sites, and ask on the mailing list.