You probably don't even need a library. Windows has an IPC mechanism built deeply into its core APIs (windows.h). You can basically post a windows message into the message-queue of a different processes main window. Windows even defines a standard message to do just that: WM_COPYDATA.
- MSDN docu on WM_COPYDATA
- MSDN demo code
- More demo code the following StackOverflow response
The sending process basically does:
The receiving process (window):
- On Vista and later has to modify its message filter using ChangeWindowsMessageEx
- Override its WindowProc
- In order to handle the incoming WM_COPYDATA
