Sending Messages to Windows in another process

Hi

I have a .exe which receives data on a serial port, does some checking and formatting and passes the data on.
Its dedicated task is just this, however I need to send the data to another application (.exe) so that it can render
the data for graphical display. Is it possible to send/post to the HWND of the second app. i.e. from process A to
process B. What implications for the data? simple strings!

Another way I thought was to use sockets and pass the data this way, does anyone know of
any better ways to acheive this?

Thanks

LittlePerson