IIRC, KDE was created because Motif/CDE were proprietary, but QT was free and had an open-source license, but wasn't compatible with the GPL. There was an agree

IIRC, KDE was created because Motif/CDE were proprietary, but QT was free and had an open-source license, but wasn't compatible with the GPL. There was an agreement with Troltech, the creators of QT that would make QT available under a BSD-style license if they didn't release a free/open-source version after a year. GNOME was created because of license issues with QT not being compatible with the GPL, so GNOME used GTK which was created by the GIMP project because Motif wasn't free.