In a Previous Age, there were “rumors that there would be interest in opening up the language if there would be enough community response around it”—wonder if they amounted to anything [1]. Interest in k is only growing it appears.
The 32 bit version of k4/q is free from Kx (the original K people) is now free from http://kx.com
There's a GPL implementation of K3 called Kona at https://github.com/kevinlawler/kona ; kevin lawler also has a language called kerf (not open source) that is based on the same principles with a different syntax (JSON+SQL+more).
In a Previous Age, there were “rumors that there would be interest in opening up the language if there would be enough community response around it”—wonder if they amounted to anything [1]. Interest in k is only growing it appears.
[1] http://www.kuro5hin.org/story/2002/11/14/22741/791