SVN

SVN and Apache WebDAV
http://www.onlamp.com/pub/a/apache/2005/07/07/apache_svn.html?page=last∞

RCS

A quick howto
1. create an RCS directory
2. check in a file ci -w author -l filename
3. display revisions rlog filename or rlog -h filename for current version
4. check out a file co -l filename
5. make changes
6. check in the file again ci -w author -l filename
7. to diff the current file with latest in RCS rcsdiff filename
8. To discard the RCS lock, rcs -u filename

If rcs complains 'no lock set by user', do these

Then just check in again.