Kona released: Open source K3.2 [screencast]
youtube.com
youtube.com
http://thesweeheng.wordpress.com/2008/11/30/more-sudoku-solv...
or game of life:
http://groups.google.com/group/personal-kdbplus
That one is mostly for "q", a proprietary follow-up language.
There's also the "k idioms", which are always educational: