Sccs.vim is a project mainly written in Vim Script, it's free.
Compare delta's from SCCS files, visually selectable
This is a mirror of http://www.vim.org/scripts/script.php?script_id=939
A scipt that interfaces with SCCS to view differences between revisions. It is not as complete as sccs-menu.vim vimscript #43, but it adds the benefit of visually selection of delta's, no need to remember relevant version numbers.
Summary of it's use: ,s Compares the current file with the last stored revision ,S Compares current file with visually selectable revision ,R Compares two visually selectable revisions