both Perl Moks and Everything are based on the same platform

Frequently given answers to such statements go in the direction that PM and E2 have started from the same codebase, but have a long history of incompatible changes. Or, quoting Wikipedia: Perlmonks:

The code that the site runs on is a much hacked fork of an early version of the Everything Engine and was created by Nathan Oostendorp as part of Blockstackers Intergalactic — the firm that also ran Slashdot. As a result, PerlMonks has many features in common with both Everything2 and Slashdot

I don't know a single line of E2 or PM code, but it is VERY OLD code that should be handled with a lot of care.

Alexander