This tool allows you to set keys, macros, and lighting for GK6X keyboards (GK64, GK84, GK61, etc). This can be used as an alternative to the official software http://www.jikedingzhi.com/downloadlist?driverID=41latest
It should work on Windows, Mac, and Linux (though only Windows has been tested so far).
When you open the program it will connect to your keyboard. Once it has connected it will create a file UserData/YOUR_MODEL_ID.txt. This can be used to configure the keyboard. See Sample.txt for examples of setting keys, macros, and lighting. Use the 'map' command to apply your changes to the keyboard, and 'unmap' to reset your keyboard to the default state (NOTE: There is no 'apply failed' message like there is on the official software, so it can fail silently!).
You can reprogram the base layer and layers 1-3 (and the Fn keys). The 'driver' layer isn't supported. The firmware doesn't allow you to reprogram the Fn keys on the base layer (which sucks!).
https://github.com/wgwoods/gk64-python - thanks to @wgwoods for his work on annotating the dissasembly of the GK64 firmware.