OTTHUNDERDOME or OTTD for short is a distant relative of a chain of spinoffs that is well known for being the antithesis of OT. Several incidents between the two forums have lead to the occasional strained relationship, but besides that the forum has hardly ever been brought up. OTTD is by far the most well known and most active forum in the chain of forums it hails from to date.
OTTD has been chugging along for almost two years now, although it was originally inactive. Since its creation, it has amassed almost 200,000 posts, by far making it the most successful forum that is even vaguely related to ROT period. Quite a large number of "decently known" OT'ers have at one point posted there, including but not limited to Skellor, Zacmaq, RD101. The site itself was run by former OTer -- and the man who pretty much brought the forum down back in 2009 -- Amsk8r, hence why the site doesn't die. However, the website was for a time "killed" by amsk8r, in that the community was forced to move to another domain temporarily while amsk8r converted to literal communist. The new forum was created by Oaky (SethiXzon) and since then efforts to restore the forum have been successful.
Part of what makes the forum notorious among the ROT crowd is its supposedly unfair bans, which many have been led to believe are handed out like candy on Halloween. However, this is not quite the case, as the only ROT users that have ever been banned from OTTD are either inactive or EminentDoom, and the bans all lined up perfectly with the forum's sole rule of "don't be a faggot." As of late though, with the lack of ROTers on OTTD and vice versa, claims of unfair bans are nonexistent, and the last claim of one was, as a matter of fact, in the case of Eminent's ban.
OT Wiki Raid
Another part of why OTTD is so hated on OT is because one day in March of 2014, some members of OTTD "hacked" WikiElephant, the creator of OT Wiki, blocked the rest of the admins, and mass vandalized many pages and deleted half of the pages. This absolute devastation of the wiki is something it has yet to recover from in full, as many parts of the wiki were irreparably crushed in the process and have never lived up to their full potential since.
In February of 2014, OTTD was thrust into the spotlight once again when semi-resident user FlamingDinner supposedly demolished the eponymous Rejected, which had been made by Zacmac. Many members, as well several subforums were annihilated, and were replaced by others mocking users. Later however it was revealed to all that Zacmac had done it himself, thanks to persuasion by the boys in blue. He later made three more Rejecteds, all of which met basically the same fate as the first one.
Global Chat Spin-off Raid
On July 30th, 2014, OTTDer and former head of this wiki Carl "hacked" the newly-made WWC forum. In reality, he'd simply exploited a catastrophic flaw in Proboards, and used it to delete everything. As usual though, people bought the "hacked" explanation hook, line, and sinker, and OTTD was bombarded with the usual "OMG FUCK YOU!!!! HACKER NOOBS" that accompany those sorts of actions. The forum was subsequently remade as WWCR, and subsequently wrecked again by a non-OTTD user, to the point where it shut down all registration and then died. WWCR was then remade into New Age Politics, which also shut down all registrations, and promptly spent the rest of its days unironically circlejerking about Nazism or something edgy like that until it was recently obliterated by a ToS infraction.
An image of the first forum's annihilation can be found here.
Respect in OT
Despite the fact that nobody cares about spinoffs, more than a few people on OT pan OTTD and say that it's a bad spinoff, which mostly is because of how OTTD is everything OT isn't. Fastlane250 is cited to be one of these people, but really, he's more impartial to it than anything else, and has occasionally voiced support for OTTD's actions. That said, pretty much the only people who don't like OTTD are people who have gotten banned off of it.