Amiga workbench was similar, although cruder, starting in 1985. I think it was just happening all around at that time.
Amiga workbench may have been available in 1985, but I think the bevels were introduced around 1990, in which case they copied NeXTSTEP.
alt Hacker News
Amiga workbench may have been available in 1985, but I think the bevels were introduced around 1990, in which case they copied NeXTSTEP.