What modules and extensions are available for C#?
There are none for the language. The language is not extensible. This is a bad copy from the perlfaq that doesnt match well with C#. C# has numerous free and commercial libraries available for it. There is no CPAN equivalent for C#. C# libraries are not specific to C# but will work with any .NET language. These are often called .NET libraries. Many .NET libraries will work with both Microsoft and Mono, but some are specific to one or the other. Google is your best friend in finding libraries for C#. Also see Codeplex, Sourceforge and Mono itself.