Digital Research's GEM (Graphical Environment Manager) was a graphical shell for MS-DOS/PC-DOS, and version 1.0 for DOS could multi-task (cooperative), but further releases disabled this feature due to threats from Apple. At first it competed with MS's Windows and IBM's TopView. GEM was given new life after being incorporated into Atari's TOS for the AtariST, but like the ST, it is now 6 feet under.