By "native MOP" I really mean things like Python's metaclasses and descriptors (and whatever Ruby's equivalents are called), as opposed to an add-on library to simulate them like Moose.
A bit of apple & oranges going on here because you don't need Moose (or more precisely Class::MOP) to simulate Python metaclasses and descriptors. Because you could, if you so wished, build a Python metaclasse/descriptor based OO system in Perl's native OO.
To clarify things:
* Python comes with a pre-defined OO system with metaclasses/descriptors for dynamically building new Python classes/objects.
* Perl comes with OO lego blocks from which you build you own OO system.
* Class::MOP is a metacircular MOP mainly written in Perl using these lego blocks (it's turtles all the way down).
* A MOP (like Class::MOP) provide an API for building & managing extendable OO systems.
* Moose is an advanced OO system built on Class::MOP.
* Moose provides features like Roles, Method Modifiers, lazy attributes and many more.
There have been two attempts, that I know of, to bring (a subset of) Moose to Python:
https://pypi.python.org/pypi/bullwinkle/0.3.6
https://pypi.python.org/pypi/elk/0.2
For something comparable to Moose/Class::MOP then have a look at CLOS (Lisp).
* Some of the best languages for producing an internal DSL (dialects) don't have a "native MOP". For eg. Lisp, Rebol or Forth.
* Python & Ruby don't have native MOP's anyway :)
NB. I wonder what you mean by "native MOP" is baked-in OO? Python & Ruby OO systems do come with MOP like abilities. However for full blown (metacircular) MOP (http://en.wikipedia.org/wiki/Metaobject#Metaobject_protocol) you need to look at things like CLOS & Perl's Moose/Class::MOP.