One of the main reasons the AIX workstation machines continued to be used even after the Windows NT workstation era began was the CAD software CATIA V4 from Dassault Systèmes.

CATIA V5 was the first version to support Windows NT. However, it was a complete rewrite, resulting in a very different UI and workflows. Even the file formats were largely incompatible with V4, so the automotive industry and their suppliers stayed with CATIA V4 for many years after the release of V5. And the only way to run CATIA V4 was on a UNIX workstation.