I think prior art exists. As a specific example of a business that has solved this problem: https://www.opendesign.com https://www.opendesign.com ODA offers s

I think prior art exists. As a specific example of a business that has solved this problem: https://www.opendesign.com https://www.opendesign.com ODA offers several licenses of their CAD related data processing tools. The most expensive licence gives direct access to source and the right to compile the source, but strictly controls how that source may be used. You may want to take a peek at their licenses. The source code is available at the most expensive 'Founding' tier: https://www.opendesign.com/join https://www.opendesign.com/join The other alternative is software escrow but I would fathom you could just offer a premium license for full source code access and capture all that additional revenue yourself.