[raymondh]

As described by Alan Kay, what OOP means is encapsulation, messaging, and late-binding.

IIRC the inspiration came from multicellular organisms. A cell "encapsulates" complexity within a cell wall. The organism as a whole works by have the cells work together via "messaging". Any shared interfaces (e.g. oxygen transpiration and nutrient absorption) can be viewed as "polymorphism".

If you buy into the definition and biological analogy, then any language that implements "encapsulation, messaging or polymorphism" actually is OOP and your question is a tautology.