Neon was a ForthLanguage; stack-based, threaded-code, ObjectOriented languages for the Mac. Neon used PostfixNotation like Forth. But apparently it looked too alien to sell. NeonLanguage is a commercial programming package for the AppleMacintosh that was sold by Kriya Systems, Inc. in the mid-1980s.
There was later a PublicDomain version called YERK [NeonAndYerkAsStackBasedOo]. See also ForthObjects.
Neon died off some time ago, but its niche was filled by the OpenSource MopsLanguage.