The NLL - National Lacrosse League is a professional indoor lacrosse league with 11 teams in the US and 3 in Canada. The league is modeled around box lacrosse which is very popular in Canada. Games are played right on top of hockey ice covered with artificial turf. Actual hockey rinks are used including boards and glass and i have to say the players seem to really change in to hockey characters when they play crashing the boards and all the fun of hockey built into the lacrosse game. Teams play a 16 game schedule and all games are played on the weekend. This is Canadian style lacrosse at its finest. Some of the finest players in the world participate in the league and as more and more star American field players convert from field lacrosse following their college careers to the indoor game, fan interest for Box Lacrosse is also increasing in the US. The NLL is a major factor in that growth of interest.
You can check out the league on their web site and find a detailed history of the league. The roots of the league began in 1987 when 4 teams made up the Eagle Pro Box Lacrosse League. In 1988 the league changed names and was then known as the Major Indoor Lacrosse League (MILL). In 2000 the league relocated to New York and has been known ever since as the National Lacrosse League (NLL)