Does anyone know of a library for RDP that's written in C or Objective-C that is not GPLed?
I'm a developer for CoRD, which is a Cocoa RDP client based off rdesktop. There are no loosely-licensed RDP implementations to my knowledge. As far as I know, rdesktop is your best bet (GPL).
Very detailed RDP protocol documents are freely available from Microsoft, however it is a somewhat difficult protocol to implement from scratch, due to its lengthy history and myriad of additions. It's much harder to implement than say, RFB.
来源：https://stackoverflow.com/questions/1019236/remote-desktop-protocol-c-or-objective-c-library