VoilaSVN free edition is free of charge for commercial and non-commercial usage.

It is a Subversion search engine, administration, online diff and history navigation solution.

It aims to promote the adoption of Subversion® for IT and NON-IT users with its very user-friendly interface.

Download VoilaSVN. 

Documentation http://voilasvn.com/help/2_0/

Search Engine	- Multi-criterion search on files (ascii, text, doc, rtf, pdf, xls, doc, ppt...) by including contents, revision comments, properties and all revisions.    - Open plugin, to allow you to add your own file parser based on file extensions.
Administration	- Access rights for Apache DAV and Svnserve - User Administration for Apache and Svnserve user file
Navigation	- Tree navigation with the choice of the peg revision. - properties and history visualisation - shortcuts to allow direct access to users who do not necessarily have access rights to the root repository.
Online Diff	Compare subversion directories, files, view history and praise (or blame) text files
And	much more...
Navigation in time:   Search result: Administration screen shots: