KDE is a community that produces a free and open-source desktop environment and a wide range of applications for Unix-like systems. According to the official KDE timeline, “in 1996, Matthias Ettrich announced the creation of Kool Desktop Environment (KDE), a graphical interface for Unix systems, built with Qt and C++.” Ettrich, then a student at the University of Tübingen, launched the project on October 14, 1996 with a now-famous public email, frustrated by the inconsistent and fragmented state of graphical applications on Unix. The name was a pun on CDE, the Common Desktop Environment, which was proprietary at the time.
KDE’s technical foundation was the Qt toolkit, developed by the Norwegian company Troll Tech and first released in 1995. The KDE timeline notes that “Qt became the basis of the main KDE technologies.” Qt gave KDE a powerful, modern C++ widget library at a moment when no comparable free toolkit existed, which let the project move quickly toward a polished, integrated desktop.
That choice also produced one of the open-source movement’s defining licensing disputes. In its early years Qt was distributed under a license that allowed free use for free-software development but did not satisfy the Free Software Foundation’s definition of free software, meaning KDE’s free desktop sat on top of a toolkit that was not itself free. Critics argued this made the whole stack legally fragile. The objection was significant enough to help motivate the founding of GNOME in 1997 as a deliberately fully-free alternative built on the GTK toolkit.
The controversy was ultimately resolved through licensing changes. Troll Tech created the KDE Free Qt Foundation as a guarantee that Qt would remain available under free terms, and Qt was progressively relicensed, eventually under the GNU GPL and later the LGPL, removing the original free-software objection. The episode became a textbook example of how license terms, not just code quality, determine whether software is acceptable to the free-software community.
To represent the project legally and financially, contributors founded the nonprofit KDE e.V. in 1997 in Tübingen, Germany. KDE and GNOME went on to become the two leading free desktop environments, and their rivalry and cooperation shaped Linux desktop computing for decades, including shared cross-desktop standards that let applications from both work together.