SIMSCRIPT was developed in 1962 by Nobel Prize Laureate Harry Markowitz and his team to support an Air Force RAND project in efficient preparation of simulation models. Wide acceptance of the powerful, English-like general-purpose and simulation language Herb Karr and Harry Markowitz created an opportunity that gave birth to the Consolidated Analysis Centers Inc., C.A.C.I., who in 1964 signed an agreement with IBM to develop a new compiler for translating programs written in SIMSCRIPT, leading to SIMSCRIPT I.5.

Over the years, several generations of the SIMSCRIPT programming language emerged, starting with text-based pre-processors in SIMSCRIPT I and I.5, mainframe compilers in SIMSCRIPT II and II.5 with transformed compiler technology, enhanced development environment, and incorporated graphical subsystems and database interfaces to accommodate the new computational environments and market demands.

CACI's mission includes the development, maintenance, and worldwide sales and marketing of SIMSCRIPT II.5. Simulation packages like NETWORK II.5, SIMFACTORY II.5 and COMNET II.5 were based on SIMSCRIPT II.5. Thousands of simulation solutions worldwide have been created and are still using SIMSCRIPT II.5.

The newest technological version, SIMSCRIPT III was released in 2007 and encompasses object-orientated concepts and modularity along with the capacity to execute on the current 32-bit and the emerging 64-bit processing chips.

SIMSCRIPT III is the only simulation package (programming language + ancillary features) on the market which is specifically designed to support modular object-oriented simulation development. Model development is facilitated by the Interactive Development Environment (IDE) SimStudio, and interfaced with the compiler and the 2-D Java simulation graphics. SIMSCRIPT III can be used in broad range of simulation areas: telecommunications, simulation of factory processes, airport logistics, theater-level military training exercises with large geographical situation maps and with animated military units, flight formations, ships, etc.

SIMSCRIPT III creates portable models which can run on PC Windows platforms, UNIX workstations, and on 32-bit and 64-bit PC Linux platforms. 64-bit SIMSCRIPT platforms provide large address-space for enhanced modeling capabilities and large, high-fidelity simulation scenarios. SIMSCRIPT III also provides database interface for storing and retrieving simulation data on a data server or in the same computer system.

SIMSCRIPT III provides backward compatibility and seamless transition of the existing SIMSCRIPT II.5 models to the new technological level SIMSCRIPT III has been offered by CACI as a replacement of MODSIM III simulation language. It incorporates all the features of MODSIM III with more efficient simulation engine and run-time. CACI also provides support for automatic language conversion from MODSIM III to SIMSCRIPT III.