That's kind of a bold, hype-ish title, am I right? You're probably rolling your eyes, or saying "yeah, sure, whatever" or something like that. But give me a chance to explain...
Back in the early 1980's, if you did any "design" or "drafting" work, you were most likely working on a physical drawing board and tracing your ideas out on Vellum, Paper, or Mylar sheets using various kinds of mechanical pencil materials or maybe a Rapidograph ink applicator. Maybe you used templates and lettering guides, or shape tracers or flexible curves and those stupid-looking weights we called "ducks" or "whales". In the mid-1980's came the first real significant influx of computerized design technologies. They had weird names like AutoTrol, CADAM and so on. They were collectively termed "CAD" for Computer Aided Design. If they were connected to manufacturing machinery, they were called "CAD/CAM" for CAD + "Computer Aided Manufacturing" (or "Machining"). If they did engineer calculations from design data, they were called "CAD/CAE" some were "CAD/CAM/CAE" and some were just stupid and we called them "overpriced crap". But they were magical for their time.
Here's the snapshot of "before": These first-generation CAD/CAM/CAE systems only, I repeat ONLY, ran on UNIX platforms. Not only that, but most were tuned for specific UNIX platforms, so they were hardware specific, such as DEC, IBM, Sun or a few others (most of which are all gone now). The software alone was often in the $10,000 to $30,000 range PER SEAT. The hardware was just as expensive, or even more expensive. I worked on one system back in that era that was priced at $50,000 for the hardware "workstation" and the design software. Keep in mind that you HAD to purchase vendor support since they did not allow you to work on it yourself, often keeping many of the features, settings and capabilities secret until you paid someone to reveal them to you. Oh yeah. Good times they were not.
Then came along some scrappy little company named Autodesk and they had this cheap little CAD product called "AutoCAD" that actually ran on an IBM-PC. The other vendors laughed and tried to ignore it. I remember an IBM rep saying to us "that's a toy - a piece of crap that'll never go anywhere". I sure wish I could have recorded that for later on.
Maybe you've heard the story of the butterfly that caused a hurricane. This is very similar.
So, as this tiny little snowflake rolled through the fledgling IBM-PC "compatable" market, it began to gather some snow and grow bigger and heavier. For the peanut gallery out there: I'm not implying it was bloated. It wasn't. It became heavier with customers and customer momentum. Still a bit immature at R9, it made heads turn at R10 and R11. Then R12 came out and that snowball was now the size of a truck and rolling faster. As the UNIX market began to respond, it lost some of its footing as well. The big players started losing key developers and managers to smaller startups, all trying desperately to stir up excitement to fend off this new upstart called the "PC". Computervision stumbled, which led to Intergraph and Pro/Engineer. CADAM, Unigraphics and others started making adjustments, and even tried "realigning" licensing costs, but they caught some breathing room when Autodesk stumbled with R13. Then came R14 and it was pretty much a done deal as far as customers balling up those checks for the expensive UNIX fees, and stroking new checks to the much less expensive PC product lines.
As customers moved from UNIX to Windows and Windows NT at an increasing rate, so too did many stalwart UNIX product vendors. CAD/CAM/CAE products previously only available on UNIX were suddenly announcing PC versions. Even the most discerning NASTRAN vendors were poking at the PC market, especially as the PC hardware specs began an accelerated upgrade path.
I saw this firsthand at least four employers, and dozens of businesses I interacted with, and multiple branches of the U.S. Department of Defense: Navy, Army, Air Force, USMC, Coast Guard, even NASA.
No other PC-based CAD product had as much impact on the CAD market, and pushing customers to take the PC platform seriously. It also pointed the light on their budgets and ROI, and suddenly program managers were faced with making serious choices about continuing on with their life-draining budget expenditures, or doing some soul searching about this new PC-based direction.
The rest is history.
Is the UNIX market dead? No. Not at all. Has it scale back? Yes. Most of the major UNIX vendors from Compaq, Sun, Prime, DEC, Silicon Graphics, Helix, Unigraphics, are gone, or have been acquired and renamed. IBM, Dassault, and Integraph remain vibrant, while PTC has undergone multiple shifts in product and services offerings, but seems to be alive and well. One major change from twenty years ago has been the emergence of Siemens.
But even with these legacy companies still bouncing along, they've ported most, sometimes all, of their products to the Windows platform. Love them or hate them, that little snowflake had an impressive impact indeed.