cvs binary package in Ubuntu Focal amd64

 CVS is a version control system, which allows you to keep access
 to old versions of files (usually source code), keep a log of
 who, when, and why changes occurred, etc., like RCS or SCCS.
 It handles multiple developers, multiple directories, triggers to
 enable/log/control various operations, and can work over a wide
 area network. The texinfo manual provides further information on
 more tasks that it can perform.
 .
 There are some tasks that are not covered by CVS. They can be done in
 conjunction with CVS but will tend to require some script-writing and
 software other than CVS. These tasks are bug-tracking, build management
 (that is, make and make-like tools), and automated testing. However,
 CVS makes these tasks easier.
 .
 This package contains a CVS binary which can act as both client and
 server, although there is no CVS dæmon; to access remote repositories,
 please use :extssh: not :pserver: any more.

Source package