The python example you linked to http://eli.thegreenplace.net/2010/06/30/python-internals-add..., which shows an example of adding an 'until' keyword, requires you to recompile the python interpreter. From your article: "After making all the changes and running make, we can run the newly compiled Python and try our new until statement". Of course you can extend any language by recompiling it and creating a new interpreter. That is exactly my point! Perl lets you achieve the same thing simply by using a module from CPAN.

I don't think you have been paying attention to what I have been saying. You keep mentioning that python has strong meta-programming. I never said anything about meta-programming. Perl, python, ruby, everybody can do meta-programming. I said that Perl lets you easily modify the core language grammar via 3rd party modules. This is an extremely powerful feature, if you took a second to think about it.