It’s interesting to see LEGO discussed here independently of the terminology and platforms I got used to thinking about it in terms of during my brief foray into online LEGO communities in the early 2000s. Being introduced to the sideways/alternative building options of “SNOT” (studs not on top) and “SNIR” (studs not in row) as specific new methodologies felt revolutionary, and the fact that they were encapsulated under such definitive terms maybe made them seem more like inventions or breakthroughs.
It’s also funny in general how so many abbreviations get thrown around (below is a list including some I’m not yet familiar with); a lot of the anacronyms are of course juvenile-sounding, maybe reflecting the nature of LEGO as a toy, but the repeated reliance on abbreviations also feels slightly military-esque in a way.
Other websites which felt like they used to be the center of the online LEGO community world: https://www.lugnet.com/ (almost like a proto-Reddit, but only for LEGO), and BrickLink - Buy and sell LEGO Parts, Sets and Minifigures for buying/selling individual pieces.
I also remember there being a specific branch of the LEGO community catering to people who had a more general interest in model railroading which focused on making model railroads in LEGO, and they kept a little bit more to themselves where you wouldn’t necessarily hear about everything they were creating unless you sought it out. (Edit: here’s one of those communities I remember from that time: Welcome to PSLTC.org)
Another collaborative activity I just remembered was the Moonbase project which IIRC Lugnet organized. Different people would build modules in a stilt-elevated interconnecting moonbase, with standardized docking heights and dimensions between modules, and then sometimes combine them together during IRL meetup events. Examples I’ve found of people following the standard: My Moonbase Module – BrickBuildr
LEGO at Hafhead.com: Misc. Moonbase Modules gallery
t-reichling.de
Reddit - Dive into anything (more recent)
Combined moonbases following the standard (links here are automatically showing up as images):
https://brikwars.com/wiki/index.php?title=File:P1010360.JPG#filehistory