D3Emu is a multi-platform Diablo III server emulator written in a mix of languages. The core portion of the server is written in C++, but there is a new GUI-based server (in xcode/d3emu-cocoa) written using Objective-C++ and Cocoa libraries.
D3Emu depends on the following packages:
If you're using the Xcode project, the header paths are all relative, and it assumes you installed the protobuf library to /usr/local/lib and /usr/local/include.
I am currently working on a GUI-based implementation of d3emu for Mac using Cocoa. It's currently in an infant stage, but I expect to make some headway soon. I am more or less creating it to help aid in understanding communication between the client and server.
If you're going to make any changes, please remember to follow the Google Style Guide for C++: http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml