By whom? I know 'inside out objects' as a technique to store object attributes in lexical, class-wide, hashes - one hash per attribute.

See this post for one example.

I don't think it's original to Barrie though. It's a analogy I've come across several times outside the Perl world in either direction (closures are inside out objects, objects are inside out closures) depending on who knows what.

Not that I think it's a particularly good analogy mind...