Scott Slavik writes me of this sad news:
You can also add AutoSolid to upFront.eZine's Unhappy New Years list. Partly the economy, but also partly due to Autodesk improving AutoCAD's solid modeling ability. They haven't brought it up to par with AutoSolids, but it's been enough to reduce our profits to an unacceptable level.
We feel bad for our previously-very-happy customers, many of whom have told us that they can't/won't upgrade their AutoCAD if it doesn't have AutoSolids. We can't help that one, but to help other AutoCAD users we've made all of our products free to download (https://www.autosolids.com/downloads.htm), no strings attached.
If anyone's interested in pushing the code further, email sourcecode at autosolids dot com.