Which game studio developed the video game in which the fictional substance Tiberium  is used to purchase units and buildings?
Tiberium: Tiberium, known as Ichor to the Scrin, is a fictional substance that is central to the plot of much of the "Command & Conquer" series of real-time strategy computer games. Within each title set in the ("Tiberian Dawn", "", "", "", "", and their expansion packs), the Tiberium crystals represent both the tools and spoils of war and are used by players to purchase new units and buildings, with each of the series' factions either directly or indirectly battling for control over the crystals. Command &amp; Conquer: Command & Conquer (abbreviated as C&C or CnC) is a real-time strategy (RTS) video game franchise, first developed by Westwood Studios.
Westwood Studios