I agree - a well-designed FIX module, supporting most, if not all versions of FIX, would be a huge helper and well-embraced in this developer-heavy industry. I honestly can't believe one doesn't already exist. I'm looking for something now that I can use to act as a simulator - something I can connect to, pass order info to, and get back executions/venue rejects/etc .... looks like I'll have to start from scratch =(