Founded in 1987, the American Football League (AFL) is a professional indoor American football league.   It is the third longest-running professional football league in North America, after the Canadian Football League (CFL) and the National Football League (NFL). The AFL plays a proprietary code known as arena football, a form of indoor American football played on a 66-by-28 yard field (about a quarter of the surface area of an NFL field), with rules encouraging offensive performance, resulting in a faster-paced and higher-scoring game.