Once upon a time, Qt was GPL + commercial. A separate project - PyQt - came and was GPL + commercial too. Later, Qt became GPL + LGPL + commercial. However, Py

Once upon a time, Qt was GPL + commercial. A separate project - PyQt - came and was GPL + commercial too. Later, Qt became GPL + LGPL + commercial. However, PyQt, didn't want to add LGPL and stayed dual licensed. Qt thought "ok then, will have to do it by myself" and created an alternative to PyQt called PySide, which was GPL + LGPL + commercial. That was in Qt4 time. Then Qt5 came, and PyQt5 appeared, while PySide was still in Qt4 land. Then PySide2 happened, now known as Qt for Python.