SW vs INVENTOR

Surfaces were first. Almost 50 years ago ....
Solids actually are sets of surfaces.

There's NOTHING inside ... but just try to tell jb that <G>.

 

Umm .... the Applications Software creates
& manipulates geometry.
Kernels are things that track topology.

 

The real problem is that they are parametric. That limits things
quite a bit.
How would you like to control restraints/parameters for
surfaces with 100 * 100 (or more) control points manually?
Per surface? Yet even simple some fairly analytic surfaces, if
approximated with NURBS (or other CAD/CAM) surfaces would
be exactly such.

OTOH Their use (constrained parametric models) tend
to reduce operator problems and at least *seem* easier
to learn, at first glance. After all, all you are making is pictures,
right <G>?

Depends on what you need in the end .....

I've used both, APT quite extensively. For some applications,
even today, nothing is better.
Some CAD/CAM systems used to be able to output APT
source to some degree, BTW. CADDS, AD 2000, ANVIL 4000 ....
CADDS IV could also output Compact II to some degree.

"Source" in the context of named geometry & so forth .. not just
ISO-4343 CLDATA, or "dumb APT", which are related.