Question: Is there a tool which lets you view the source code a svn repo? 

Please let me know if you need any additional information. 

Edit : I just want to browse the repos which does not have some interface to browse the code.

Answer: 
There's some PHP based interfaces for viewing and browsing one or several svn repos.

My favorite one is [websvn](http://websvn.tigris.org) have a look and let me know if this is useful for you.
You can also combine it wit tracking system "Trac", see <http://trac.edgewall.org/>