Crystal Dynamics is best known for developing the Legacy of Kain and Gex series.[1] Although the first Legacy of Kain video game was developed by Silicon Knights,[4] Crystal Dynamics gained the rights to the franchise in 1998[5] and released four sequels between 1999 and 2003. In 2003, the studio took over the development of the best-selling Tomb Raider franchise[6] after its original developer, Core Design, failed to gain critical or commercial success with their later games.[7][8] Crystal Dynamics' first Tomb Raider game, Tomb Raider: Legend, became a commercial success with 4.5 million copies sold as of February 2009.[9] Its sequel, Tomb Raider: Underworld, sold 2.6 million copies.[9] Since 2003, the studio has developed five games in the series, encompassing two reboots of the franchise.[10]