We've had success compiling reciprocate under Visual Studio .NET version 7.0, 7.1, and 8.0 It will not work older compilers. Here's what we did:

1) Checked out the "sip" repository so that it became C:\sip on your machine.

2) In Visual Studio, opened the project file C:\sip\resiprocate_X.sln
   (where X matches the version of Visual Studio you are using)

3) Start a build