The SBURB Glitch FAQ is essentially a fanfic that aims at cataloging the various mechanics of SBURB, with a liberal amount of fanon to fill in the empty spaces. It's fairly popular, though it has some controversial elements. Mainly that it outright states that the game can't be completed and that it just loops people who "beat" the game by throwing them into other sessions that are just starting out.

Still interested, though.