AF2 (styled as af2 and short for arenafootball2) was the name of the Arena Football League's developmental league; it was founded in 1999 and played its first season in 2000. Like parent AFL, the AF2 played using the same arena football rules and style of play. League seasons ran from April through July with the postseason and ArenaCup championship in August. The AF2 continued to operate while the AFL had suspended operations. The league was effectively disbanded in September 2009 when no team committed to playing in 2010.
Like most other minor sports leagues, the AF2 existed to develop football players and also to help players adapt to the style and pace of arena football. In addition, the AF2 was similar to other minor leagues because AF2 teams played in smaller cities and smaller venues. While the AFL was played in cities like Los Angeles, New York City, Philadelphia, Dallas, and Chicago, the AF2 fielded teams in cities which are part of metropolitan statistical areas ranging in size from Milwaukee (with 1,739,497 residents) to Albany, Georgia (with 164,000 residents). Players also earned less in the AF2, with each player making $200 per game.