This is a WWW interface for CVS Repositories. You can browse the file hierarchy by picking directories (which have slashes after them, e.g., src/). If you pick a file, you will see the revision history for that file. Selecting a revision number will download that revision of the file. There is a link at each revision to display diffs between that revision and the previous one, and a form at the bottom of the page that allows you to display diffs between arbitrary revisions.