I'm looking for a way to search through our subversion repository or just packaged source code.
Are there any downloadable servers/tools like Google Code Search to index source code (preferable with support of version control systems like svn) and allow us to search in it?
Is there any tool that will index documents too?
A langauge-sensitive source code search engine can be found at SD Source Code Search Engine. It can handle many languages at the same time. Searches can be performed for patterns in a specific langauge, or patterns across languages (such as "find identifiers involving TAX"). By being sensitive to langauge tokens, the number of false positives is reduced, saving time for the user. It understands C, C++, C#, COBOL, Java, ECMAScript, Java, XML, Verilog, VHDL, and a number of other languages.
I use glimpse for code search. I use the free command line tool, and not the paid web interface. It's very quick, and can be combined with other tools to quickly find what your looking for. I find it's easy to setup multiple repositories for different branches of the code. Additionally, I've created a few scripts to help query, format, and colorize the results.