• Ultimate Fighting Championship
The UFC is a U.S.-based mixed martial arts organization, which was started as a tournament to find the world's best fighter, no matter his style. Although there were some rules, the UFC was initially known as no-holds-barred fighting. The organization has since reformed itself and is now sanctioned by athletic commissions.
• International Fight League
The IFL is the first team-based professional mixed martial arts league. Twelve IFL teams compete during the regular season, with the four teams posting the best records advancing to the semifinals. IFL bouts are held in an oversized boxing ring, with three four-minute rounds.
• Elite Xtreme Combat
EliteXC was founded in 2006 as the first mixed martial arts promotion to have its events televised live on premium cable TV. The first EliteXC show will feature a main event of Renzo Gracie versus Frank Shamrock and be carried by Showtime. The promotion is expected to stage six shows in 2007.
• World Extreme Cagefighting
The WEC was purchased in late 2006 by Zuffa, LLC, which also owns the UFC. Zuffa is running the WEC as a competing promotion to the UFC, with its own stable of fighters and champions. The WEC was launched in 2001 and staged two dozen events before being purchased by Zuffa.