Qt is a nice C++ framework with a GUI toolkit on top, actually, 2 toolkits, Widgets and Qml. Qt is available under the GPL and LPGL, open source licenses and a closed source license. Back in 2020, the Qt company decided to start a war against their own users and contributors by witholding the 5.15 code, only releasing them under a closed license, making the offline installers available to paid customers and requiring a Qt account for the online installer. Due to an agreement with the KDE project they are obliged to release the code after one year under an open source license, and that time has come for 5.15.3. For most LTS releases, the Qt company writes a blogpost, but this open source release only gets a mailing list post (One day and 4 blog posts later, no mention of 5.15.3 on their blog). This short post is intended to give a bit more publicity to that release and to tell you about the KDE Qt 5.15 LTS patch collection. Even if I might not agree with the business practices, the framework is nice to work with.

I have a strong opinion on how the Qt company handles licensing, but that doesn’t
really adds something cons