“I wrote a program that takes any text and tries to find any accidental limericks that might be hiding within (based on syllable counts and rhyme, ignoring punctuation and intent).
Limericks have a fairly loose form. The rhyme scheme is always AABBA, but the syllable count can be anything along the lines of 7-or-8-or-9/7-or-8-or-9/5-or-6/5-or-6/7-or-8-or-9. And as if that weren’t loosey-goosey enough, they can have either anapaestic meter (duh-duh-DUM, duh-duh-DUM) or amphibrachic meter (duh-DUM-duh, duh-DUM-duh)!
…(So) Nantucket is set to look for limericks that are AABBA (rhyme scheme) and 8/8/5/5/9 (syllable count per line). It currently ignores meter, but I may add that requirement in later. It also only looks at words through an American English accent.” (Danielle Sucher, via Neal Stephenson)