503
free ruleware
(lemmy.blahaj.zone)
Be sure to follow the rule before you head out.
Rule: You must post before you leave.
It's probably a mix of that and how CAD/Engineering software is a complicated niche market. It's not as ubiquitous as something like an office suite or even a phot editor like GIMP. I don't have anything to back that up other than a hunch.