Simplify the following text for a Grade 13 native English-speaking person.
Original: Immediately following this European tour , they played the main stage at Ozzfest 2006 alongside DragonForce , Lacuna Coil , Avenged Sevenfold , Disturbed , and co-headliners System of a Down .
Simplified: They also played the main stage at Ozzfest 2006 alongside bands such as DragonForce , Lacuna Coil , Avenged Sevenfold , Disturbed , and the co-headliners System of a Down .