For old-school mod_perl apps setting MaxRequestsPerChild was often a much better ROI than actually finding and fixing the leaks.

Speaking as somebody who's done over a decade of large scale OO applications perl and is actually really good at finding and fixing the leaks, this has often been intellectually aggravating but every time I've set that option instead I rewarded myself with a glass of bourbon for picking the pragmatic choice and then went back to adding (non-leaky) features that were far more useful to the company in question than cleaning up the older code would've been.

It's not a bug, it's a pattern.

Seriously though, IIS 5.0 had no worker recycling. There was no method to fix the issue. Threads would eat up GB's of memory until you killed them.