(Extended Three-dimensional Analysis of Building Systems) is a proprietary structural engineering software developed by Computers and Structures, Inc. (CSI). Version 9.7.4 (often mistakenly written as "97 4") is a legacy release from approximately 2008-2010.

Structural engineers often choose between these two industry-leading tools based on project type.

CSI allows network licenses to be used on portable computers. You can install ETABS legally on a USB drive (using the full installer) and check out a license from your firm’s server. No cracking required.