Useful libraries of C# programs?

http://www.codeguru.com/csharp/

http://msdn.microsoft.com/en-us/library/67ef8sbd(VS.80).aspx

http://msdn.microsoft.com/en-us/vcsharp/aa336738.aspx

http://www.developer.com/net/csharp/

http://code.msdn.microsoft.com/default.aspx?SiteEntry=gdn

http://planetsourcecode.com/vb/scripts/BrowseCategoryOrSearchResults.asp?lngWId=10&B1=Quick+Search&txtCriteria=C%23&blnWorldDropDownUsed=TRUE&txtMaxNumberOfEntriesPerPage=10&blnResetAllVariables=TRUE&optSort=Alphabetical

http://www.codebeach.com/index.asp?TabID=1&CategoryID=15

http://www.mastercsharp.com/topic.aspx?TopicID=4

http://csharp-source.net/

http://www.csharpfriends.com/