I have several different versions of the same software (written in .Net/WPF) that interact with different brands of hardware. I decided to discontinue one of the platforms. The company that sells the hardware for that platform approached me about purchasing the software source code from me so they can continue to sell the software to their customers.
So, I would rework the UI and rebrand it so it doesn't look exactly like the other versions of the software, and they could claim it as their own. My question is, is there a way for me to sell and give them the source, without putting myself in legal danger since 50% of the source code is still in use with the other versions of the program I will continue selling?
The client is fully aware of the situation, and is not interested in exclusive rights to the code. They just want to be able to take it over (and modify it if need be) so they can continue to sell it.