KISS is aimed to be a conforming ISLisp processor.
The development is at the initial stage.

The current KISS is an interpreter written in C and ISLisp by Yuji Minejima.

See also the public domain draft of the ISlisp specification
https://github.com/nenbutsu/ISLispHyperDraft
https://nenbutsu.github.io/ISLispHyperDraft/islisp-v23.html