KDE was originally developed after Matthias Ettrich founded the project in 1996.
Ettrich proposed a “consistent, nice-looking” free desktop environment for Unix-like systems after becoming frustrated that Unix applications often looked and behaved differently. His idea was influenced by the commercial Common Desktop Environment, or CDE, but KDE aimed to provide an integrated open-source alternative.
The project was initially called the Kool Desktop Environment and used Qt, a graphical application framework developed by Trolltech. Qt made it practical to build a coordinated suite of desktop applications in C++, giving KDE a consistent visual and technical foundation. The first major KDE release, version 1.0, appeared in 1998.
KDE is not the same thing as a single application: it grew into a broad desktop project containing a window manager, system tools, libraries, and applications. The project later adopted the name KDE as a broader community and technology brand, while its modern desktop workspace became known as Plasma. Ettrich also founded LyX, a graphical frontend for LaTeX, before and alongside his work on KDE.