We recently reworked an app developed in mid 2000's and had the delightful job of working through layer upon layer of abstraction and bad OOP (this was when OOP was becoming en-vogue), but a lot of these apps were written in PHP 4, so they mimicked 5.x with hacks... which then were used to implement abstraction.

Yeah, they turned a procedural language into some half-baked-kinda-sorta-looks-like-OOP project in just under 53,000 lines of code.

That kind of "mimic".