Back in the early 90s, I was part of a team that built facilities management software for the Burnet Road IBM facility in Austin. This place was home of the RS/6000. Part of our task was to convert drawings for about four million square feet of facility space from CADAM software [CAD running on mainframe] to AES software [CAD running on the RS/6000]. If I remember correctly, we exported from CADAM to .dxf > .dxf into Microstation > ran some automated Microstation processing > expoorted from the resulting Microstation to .dxf > .dxf to AES > post processing the AES files with the native AES language. We wrote a frontend for managing the Oracle database full of department, facility space, and employee info. The database info was stored as graphical information on the CAD drawings. We also wrote a method of querrying the database, with plain English sentences, and getting answers as graphical information on the CAD drawings. Database updates ran every night based on that days entries through the GUI interface of CAD drawings.