KDE () is an international free software community that develops Free and Libre software. Well-known products include the Plasma Desktop, KDE Frameworks and a range of cross-platform applications designed to run on modern Unix-like and Microsoft Windows systems. It further provides tools and documentation for developers that enables them to write software. This supporting role makes KDE a central development hub and home for many popular applications and projects like Calligra Suite, Krita or digiKam. 

The Plasma Desktop, being one of the most recognized projects of KDE, is the default desktop environment on many Linux distributions, such as openSUSE, Mageia, Chakra, Kubuntu, Manjaro Linux, and PCLinuxOS. It was also the default desktop environment on PC-BSD, but was later replaced with Lumina, a desktop environment which, like KDE, is written in C++ and Qt. 

The work of the KDE community can be measured in the following figures: 

K Desktop Environment (KDE) was founded in 1996 by Matthias Ettrich, who was then a student at the Eberhard Karls University of Tübingen. At the time, he was troubled by certain aspects of the Unix desktop. Among his concerns was that none of the applications looked, felt, or worked alike. He proposed the creation of not merely a set of applications but a desktop environment in which users could expect things to look, feel, and work consistently. He also wanted to make this desktop easy to use; one of his complaints about desktop applications of the time was that it is too complicated for end user. His initial Usenet post spurred a lot of interest, and the KDE project was born.
What is one well known product?
Plasma Desktop,