Complex sentence: In addition to two main stages, secondary venues were available including several alternate stages, a night-time rave music tent and a film festival (sponsored by the Independent Film Channel) held in a former airplane hangar.
Split into simpler sentences: In addition to two main stages, secondary venues were available. This included several alternate stages, a night-time rave music tent, and a film festival (sponsored by the Independent Film Channel) held in a former airplane hangar.