[lolive]

Stanford universiry manages a tool called Protege (cf protege.stanford.edu). It is now fully RDF/OWL, I presume. But in the last decade, there was a dedicated version for FRAMES. (I Think this link is still valid: https://protege.stanford.edu/download/protege/3.4/installany...)

[rjsw]

A stage inbetween Frames in Lisp and RDF/OWL was KIF [1].

[1] https://en.wikipedia.org/wiki/Knowledge_Interchange_Format