PC GEM/1 is the original PC release and is reasonably close to the atari ST release.. It has more than 2 movable windows and a trash can.
PC GEM/2 was crippled (ie. only 2 fixed windows and no trash) because Apple sued DR over the look and feel of the PC/GEM being too much like MacOS. Of course this was the death of GEM really.. and it only ever surfaced on the PC again as a glorified filemanager in the latter DR DOS as Viewmax. Since most of GEM was written by a fellow at DR who came across from Xerox Parc himself.. and a good deal before MacOS was ever released.. its just another sordid discusting tale from Apple paranoid business practices. Maybe we should consider ourselves fortunate that Apple didn't turn their attention to Atari GEM otherwise history might have been considerably different.
Its totally unfair to compare PC/GEM to what we have now in terms of AES's VDI's etc... because these are mostly replacement components. They weren't written in 1985. No development work has really been done on DR's GEM since the late 80's.
Also with regard to porting MINT as the kernal using JET. The other option is to use PCGEM/1 GEMDOS code thats been GPL'd. There was a previous poster refering to EmuTOS.. that has done just that. It appears to look good.. but needs some atari BIOS/XBIOS stuff added. eg.. LineA. I would agree really that we already have VDI/AES/Desktop open source code... so thats really GEM anyway.. the kernal is the trick.. MINT or TOS(PC GEMDOS+BIOS+XBIOS etc)?.. or NetBSD for that matter? If we are going to port to a new architecture... then all our existing code breaks.. and I can't really see the need for TOS compatibility.. of course we need GEM.