This subdirectory formerly contained tools that can be used with CVS.
In particular, it used to contain a copy of pcl-cvs version 1.x.
Pcl-cvs is an Emacs interface to CVS.

If you are looking for pcl-cvs, we'd suggest pcl-cvs version 2.x, at:
    ftp://ftp.weird.com/pub/local/

Both of the following CVS sites have a page about pcl-cvs:
    http://www.loria.fr/~molli/cvs-index.html
    http://www.cyclic.com/
They also have much information about CVS tools more generally.
