is the K Desktop Environment. It is a project initiated by Matthias Ettrich in 1996. The aim of the project is to connect the power of the operating systems with the comfort of a modern user interface.
In short, will bring to the desktop!
If you want further information about , have a look at What is ?
It stands for Kool. Take a look at the message that started it all.
is a Desktop Environment for all flavors of . While it is true that most developers use , runs smoothly on a wide range of systems. You may, however, need to tweak the source code a bit to get to compile on a not-so-popular variant of , or if you are not using the development tools, in particular the compiler.
Some of systems on which is running are:
FreeBSD
MKLinux
No, is not a window manager. While includes a very sophisticated window manager ( in before version 2 and in version 2 and above), is much more than that. It is a full-blown Integrated Desktop Environment.
provides a complete desktop environment, including a file manager, a window manager, a help system, a configuration system, uncountable tools and utilities, and an ever increasing number of applications, including but not limited to mail and news clients, drawing programs, a and a viewer and so forth.
No, is not a clone. Specifically is not a CDE or clone. While the developers have and will continue to glean the best features from all existing desktop environments, is a truly unique environment that has and will continue to go its own way.
Yes, is free software according to the General Public License. All libraries are available under the LGPL making commercial software development for the desktop possible, but all applications are licensed under the GPL.
KDE uses the C++ crossplatform toolkit, which is also released (since version 2.2) under the GPL.
It is absolutely legal to make and available on free of charge. No runtime fees of any kind are incurred.