If you're the only author involved (or if all authors, including those of downstream dependencies, agree), you can dual-license the software: AGPLv3 by default, proprietary for paid-up customers.<p>So: whatever you put on GitHub (or wherever) is available for anyone to use for any purpose, as long as they re-contribute their changes to your code and/or the source code for directly-linked projects.<p>To anyone who doesn't want to meet those obligations, you can offer a proprietary license, allowing them to use the code in any way you see fit.<p>Turning this into a sustainable business, however, <i>may</i> be a challenge. So, some questions to consider: <i>why</i> do you want to open-source? Because you have existing dependencies? Existing contributors? Or just because it sounds good?<p>If the latter, just forget about it, and go full-proprietary: nobody will care. If you depend on contributors that might insist on open-sourcing their code, talk to them to figure out the best way forward. And if it's because of dependencies: you'll have to respect their license, and good luck with building a business on top of that...