KQ is a console-style role playing game, similar to Final Fantasy. It is composed of the KQ engine, and several map and script files that make up the world. The entirety of KQ is licensed under the GNU GPL v2.
KQ is not finished. However, what is done still makes a fun game that takes several hours to "complete." You know you are done when everywhere you go, you get messages such as "There should be a castle here," or "Todo:..."
To start playing, you can download a source tarball or binary from http://sourceforge.net/project/showfiles.php?group_id=61344. Or you can download the latest cvs version. If you use Linux, you may be able to download a binary package from your Linux distribution.
If you want to learn more about the KQ world, see GameInfo. Do not read these files if you want to avoid spoilers.