ACIS

ACIS is the historical second commercial geometry kernel, developed by Spatial Technology in the late 1980s and now owned by Dassault Systèmes. ACIS underpins AutoCAD, Autodesk Inventor, and many lightweight CAD/CAM applications. Its source tree was forked twice in the 1990s — Autodesk's ShapeManager (subject of a long-running lawsuit) and CoCreate's SolidDesigner (now part of PTC's Creo Elements/Direct line) — making ACIS the historically most-forked kernel codebase in MCAD.

Why it matters

ACIS's relative decline in seat share against Parasolid illustrates that kernel quality alone does not determine market position. Distribution, licensing terms, and the strategic posture of the parent company matter more — and Spatial's ownership-chain history (UGS to Dassault) is the through-line that explains both ACIS's retreat and Parasolid's expansion across the same window.

Related concepts

Cite this definition

Finocchiaro, Michael. “ACIS.” DemystifyingPLM PLM Glossary, 2026, https://www.demystifyingplm.com/glossary/acis