The K Desktop Environment (KDE) is a well known Free Software desktop environment. It is default on some distributions of Linux, such as Mepis. It can be installed in Debian as well, though GNOME is the default.
KDE comes with a fairly extensive collection of software, including Kate, a text editor; KStars, a planetarium application; Konqueror, a web browser; KMail, a mail client; and many other basic applications usually beginning with K.
On January 11, 2008, KDE 4 will be released. It is a major revision of the previous versions. It is said to be much more processor and memory efficient as well as having a better looking GUI. It is based off of the QT 4 desktop environment.