Looks like they have Mac, Windows and Ipad downloads, haven't tried it yet but looks interesting.
They've also opened up some of their other 3d design tools:
The tinkercad looks amusing.
They do a pretty good job of hiding the link to the TOS until you download it but it appears the free is only for non commercial use and has some other limitations on use:
The premium is about $100/yr though so that doesn't seem horrible for cad licensing and at least you can try before you buy.