SCCS (
Source Code Control System) is the original
Unix revision control system. It is generally
obsolete and is not appropriate for new projects;
RCS does the same job, only better, and
CVS is in a different league entirely. Also, many older implementations of SCCS have
Y2K issues, so it really should be avoided if at all possible. The main difference between RCS and SCCS in the way revision information is stored. SCCS stores the original content, and the changes of each subsequent revsion. RCS, on the other hand, stores the current content, and the changes to go back to each previous revision. Since the current contents are generally needed more often than old revisions, SCCS has to do a lot more work to do the most common VC tasks.
SCCS stores a file's historical data in a file called s.filename, where filename is the name of the file. This coresponds to the filename,v files of RCS. The commands delta and get are SCCS's versions of ci (checkin) and co (checkout).
SCCS is included with most commerical Unices such as Solaris, AIX, and HP/UX. There is also a GNU version of SCCS available called CSSC ("Compatibly Stupid Source Control").