Computers and Structures (CSI)

Computers and Structures, Inc., known as CSI, is an American structural-engineering software company headquartered in Walnut Creek, California, and founded in 1975. Its programs are among the most widely used analysis and design tools in the profession: ETABS for buildings, SAP2000 for general structures, SAFE for floors and foundations, and CSiBridge for bridges. Engineers use them to model how a structure carries gravity, wind, and seismic loads, and to size and code-check its members across thousands of load combinations. CSI's recent releases have focused on a unified programming interface across its products, automation, and tighter exchange with building-information-modeling tools rather than on built-in artificial intelligence — its software is the rigorous analysis engine that AI assistants and optimization workflows increasingly build on top of, rather than an AI product itself. For structural engineers, CSI is one of the foundational software makers of the discipline.