are there any open source desktop sharing protocols? if so, what are they? can anybody tell me the things i would know in order to implement a protocol e.g if i want to write a desktop sharing protocol what are the things i need to know and from where i should begin.(preferred languages Java, C++ and C#)
Thanks !!
RFB is the protocol used in VNC applications, and it is an open specification.
A protocol is just a language that networked applications 'agree' to speak. That is to say, because both ends of the connection are speaking the same language (meaning they know what bytes mean what in the communication) they are capable of sending meaningful information to one another and interpreting the information they receive.
Therefore, the first thing you should do before implementing a protocol is to learn and understand it. Often (and always in the case of open specifications) there will be a document that explains the protocol and all the ins and outs. For example, the specification for the RFB protocol can be found here.
Read it and implement a program that can understand RFB and you will have created an RFB implementation.
As for the preferred language bit: a protocol doesn't stipulate what language the protocol is implemented in, just the way that communication takes place, so you can implement it in whatever language you wish.