I'd like to know this information for IIS versions 6.0, 7.0 and 7.5.
                +8 
                A: 
                
                
              
            Probably C++, the core that is, newer versions such as 7 might have extensions written in other languages from the .NET family.
                  Filip Ekberg
                   2009-11-12 10:20:29
                
              
                +3 
                A: 
                
                
              It is made in C++, microsoft has given isapi extension which is api for IIS and programmers can explore classes using this api
                  ganesh
                   2009-11-12 10:48:43
                
              hmm.. he accepted your respons and not mine, funny :)
                  Filip Ekberg
                   2009-11-12 12:04:17
                Not so funny. Your response was "probably" and "might".Ganesh's response was "It is" and a brief proof.
                  FerretallicA
                   2010-01-13 00:04:57