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/

The following CVS site has a page about pcl-cvs:
    http://ximbiot.com
It also has much information about CVS tools more generally.
