ViewSVN provides simple and easy to set up web interface for viewing SVN repositories. Some features are: directory/file browsing at different revisions, diffing and log viewing.
It uses svn commandline tools so it works without direct repository access (but that can be used as well). The downside is that it may be rather slow, but hopefully that will be fixed in the future.
If you are looking for a feature-rich and robust subversion repository browser, this one is not for you. Try ViewCVS instead.
These details are provided for information only. No information here is legal advice and should not be used as such.