Mod The Sims
ModTheSims2 (MTS2) was founded by Delphy in May 2004. MTS2 focuses on custom content, most notably Game Modifications. It also has tutorials to make said modifications.
It's sister site, Sims 2 Community appeared around July 2005. The purpose of this was to alleviate the social threads on MTS2, so MTS2 could focus on modifying the game. However, in May 2009 MTS2 and Sims 2 Community were merged into one site again. This was because staff on both sites felt that the line between the two sites was bluring and disliked having to send people to the other site constantly, to have their questions answered.
Other Sites Hosted by MTS2
MTS2 also hosts other sites on its server, such as MikeInside, TS2 InSIMenator, Simsistic Downloads!, Sims2Pack Clean Installer, Helaene, and Sapphire Sims 2. Even though it's not listed, MTS2 also hosts More Awesome Than You.
Content
Modthesims 2 boasts content for mods, pets, sims, furniture and build mode.
Adult Content
While adult content and less risque content used to be in the same place, adult content was firstly moved to a different section of the site and then given it's own site, SexySims2, for the benefit users of the site who want to spice up their game in a different way.
Availability
You must be a member to download from and post on ModTheSims2. Membership is free as it is their philosophy to provide their service at no cost the the end user[1]. There is a donation button and 'MTS2 Supporter/Fan/Addict' monthly subscriptions. These are optional with the only advantages to having a subscription being less ads, a larger avatar and a custom title.