A binary analysis tool like a decompiler is incomplete without a programming interface.Sure, decompilers tremendously facilitate binary analysis. You can concentrateof the program logic expressed in a familiar way. Just add comments, rename variablesand functions to get almost the original source code, almost perfect. However, quite often thereis a small ugly detail and the output falls short of being satisfactory.

http://hexblog.com/2007/10/hexrays_sdk_is_ready.html