Virtual reality worlds were created by University of Illinois students in CS 498SL: Virtual Reality. This course was taught in the spring 2015 semester by CS Professor Steven LaValle. In fall 2014 LaValle returned to Illinois following an extended leave during which he served as head scientist at Oculus, developer of the Oculus Rift virtual reality headset. Oculus was acquired by Facebook in 2014 for $2 billion.