While using ildasm.exe is a very common task when you wish to dig into the guts of a .NET assembly, the one gotcha is that you are only able to view the underlying CIL code, rather than looking at an assembly's implementation using your managed language of choice. Thankfully, many .NET object browsers and decompilers are available for download, including the very popular Reflector.
This free tool can be downloaded from http://www.red-gate.com/products/reflector. Once you have unzipped the archive, you are able to run the tool and plug in any assembly you wish using the File | Open menu option. Figure 1-11 shows our Calc.exe application once again.