how to figure out the code source watermark of a binary?

Recently I found a software call MyIM which acts like Gaim/Miranda as to put together MSN/ICQ/AIM, and I just got interested to figure out where MyIM's protocol model is copied from GNU(Gaim, Miranda, KMess, Jabber,...).

But MyIM just put all protocol modules inside with the GUI exe. The MyIM.exe seems be built with with VC(not sure if 6 or 7).

Anybody of any hints for me to go a step further?

The install package could dl from hxxp://www.myim.com.cn/downloads/MyIMBeta.exe, while here I attached the single exe in case some one hate to installation like me