> On a side note, it makes me think of the Qt business model. That's the major example Stallman cited in his article about selling exceptions to the GPL. http

> On a side note, it makes me think of the Qt business model. That's the major example Stallman cited in his article about selling exceptions to the GPL. https://www.gnu.org/philosophy/selling-exceptions.html https://www.gnu.org/philosophy/selling-exceptions.html > The KDE desktop was developed in the 90s based on the Qt library. Qt was proprietary software, and TrollTech charged for permission to embed it in proprietary applications. TrollTech allowed gratis use of Qt in free applications, but this did not make it free/libre software. Completely free operating systems therefore could not include Qt, so they could not use KDE either. > In 1998, the management of TrollTech recognized that they could make Qt free software and continue charging for permission to embed it in proprietary software. I do not recall whether the suggestion came from me, but I certainly was happy to see the change, which made it possible to use Qt and thus KDE in the free software world. > Initially, they used their own license, the Q Public License (QPL)—quite restrictive as free software licenses go, and incompatible with the GNU GPL. Later they switched to the GNU GPL; I think I had explained to them that it would work for the purpose.