source code

you can find open-source and free projects (including asp.net/.net/mvc) here

There are others source code search engines and repositories:

codefetch{ - www.codefetch.com/
Snipplr - Code 2.0 - snipplr.com/
Google Code Search - www.google.com/codesearch
Codase - Source Code Search Engine - www.codase.com/
Home | byteMyCode - www.bytemycode.com/
DZone Snippets: Store, sort and share source code, with tag goodness - snippets.dzone.com/
Krugle - Find code. Find answers. - www.krugle.com/
Wiki Engines - c2.com/cgi/wiki?WikiEngines
merobase ? Software Component Finder - www.merobase.com/
Code Snippets - Source Code | DreamInCode.net - www.dreamincode.net/code/browse.php?cid=0
Open Source Code Search Engine - Koders - www.koders.com/
Code Search - O'Reilly Labs - labs.oreilly.com/code/