It might exist but open-core model ( https://en.wikipedia.org/wiki/Open-core_model ) is much more commmn. I went through QT project licensing FAQ and I still don't see any situation when I would be forced to pay for commercial license when creating commercial software. Some SO answers suggest that complying with LGPL is harder on mobile OSes. Anyway - if you release something on open license, you can't really limit its use, no matter how your second license is constructed. That is probably why paid add-ons are so popular.