This is the design of our Opie PDA Communication Protocol It's main purpose is to be src compatible with QCOP from TT and Qtopia. It's main target is to be used as a QCOP replacement for the X11 Windowing System. We heavily use unix domain sockets for the internal communication. We've one socket in $HOME/.opie.cop which is the server socket. We will communicate with the use of QDataStream and QByteArray. Internally QByteArries will be copied from the client to the server A package is looking similiar to this one int packet_type; // Register, Unregister, Call, Method, Reply, RegisterChannel, UnregisterChannel QString channel; QString header QByteArray packet Server PART: We keep the fds together with a list of Channels QMap> int is the fd and QString is the channel name this makes the isRegistered stuff more easy to manage Client: RPC is currently not enabled but will be available in future versions I do not want to add it otherwise I'll stick too tight to this implementation. We currently only support send and forget isRegistered will be taken care of the client side. We can not use the X WindowSystem for that I hope this helps... be sure to look at the code I try to comment it and now go to the hacking ;) -zecke 30.09.02