My favorite wiki at the moment is the wikipedia,
which I see already has an entry describing perl: http://www.wikipedia.org/w/wiki.phtml?search=perl&go=Go
Incidentally (or maybe not) anything you might want to say
about perl could be added to the wikipedia as an additional
node, linked to from this page.
Arguably it would be contrary to the spirit of the wikipedia
to get *too* detailed, though.