Consider opensourcing your project. I think you'll have far more to gain than ever lose. Look at what Microsoft is doing. All of .Net may be opensourced within 5 yrs and then it will get optimized for Linux and OS X. That process is occurring already for what they have released. Your value is you, your ability to innovate and problem solve, not your code. You want to sell yourself to a quant place? IMO, there's your opportunity.
Absolutely true...there are many crappy trading platforms out there in need of improvement. It would be nearly impossible for him alone to finish development, and then sell or open-source the work. He'd need an army of techies to handle the support aspect.