Sierra Creative Interpreter (and sometimes SCript Interpreter) is a virtual machine for executing platform independent and object oriented code. It was developed by Sierra to run several of their game titles, e.g. Space Quest 3-6, Police Quest 2-3, Leisure Suit Larry 2-7, King's Quest 4-6, Quest for Glory 1-4, Hoyle's Book of Games 1-2, The Colenel's Bequest, Conquest of Camelot and Codename: Iceman. SCI replaced Sierra's earlier interpeter AGI (Adventure Game Interpreter), and was originally designed for 16 bit little-endian computers.

SCI0
Was used in the first SCI games. Uses vector drawn EGA graphics, MIDI sound and typing interface
SCI01
Uses digital sound effects, mouse support and new compression
SCI1
Uses bitmapped VGA graphics, 100% point-and-click interface and new compression
SCI32
Uses a 32 bit engine, supports higher resolutions than 320x200 and digitized speech.
SCIWin
Windows version of SCI32