Leimi's note: removed lots of stuff from the original gist of scottjl, (thanks to him by the way!), as in the end some wasn't useful for me. If you are intestered, go check the gist revisions.
The KC60 is kinda like a premade GH60 that was first sold on Massdrop during summer 2015.
It runs on TMK firmware, or something based on it at least (not sure this is the real source for the keyboard but it seems it is), which means it's heavily programmable.
There is a GUI tool (the source of this tool seems to be here) and a command-line tool to ease up the process of programming the board.
**Go check this great article on Key