If an Indian hedge fund or financial institution use FIX based software, would not the exchange provide some software — in which case your products should be more about added feature — correct?
As mentioned earlier, FIX based implementations do not provide any software. FIX is a TCP/IP based messaging protocol, which includes a session protocol and an application protocol. Session protocol contains information on session initiation and maintenance, message sequence number management making sure that messages are not lost. Application protocol layer specifies message layout for different trading messages like Orders, Cancels, Execution Reports etc. Please take a look at www.fixprotocol.