This was an amazing version of FORTH for developing games on the Commodore 64. I bought White Lightning, which came with Basic Lightning, way back in 1986. This FORTH could multi-task on a Commodore 64 by specifying a FORTH word to be executed when an interrupt occurred. It even had up to 255 variable-size software sprites (blit objects).
Disk image for C64 emulators is available (a website had it named dm029.zip). Documentation is available at bombjack.org, along with other ancient Commodore artifacts.
Send me an email (follow the home link), as I'm curious how other people used it, and if White Lightning was ever used in commercial C64 games (?).