Greg was one of the greats in the roleplaying community. His Glorantha is a wholly innovative fantasy setting, unlike anything else in the gaming community: a world of myths and legends that has depth far beyond the surface of its modern-day. But Greg was more than that because he saw and embraced the creative vision in others as well. He worked with creators such as Steve Perrin and Robin Laws to design game systems for his magnificent world and he also helped to bring to life other totally disparate settings, such as Ken St. Andre's Stormbringer and Sandy Petersen's Call of Cthulhu. To be able to fulfill one's own creative vision is great, but to empower others, that goes far beyond.
I will personally remember Greg as the wise sage who supported me when I began to write about the Aldryami in the early '90s, who welcomed me into Chaosium with a smile at how little they could pay, and who would sit in his office at 950-A 56th Street, pontificating on his world, but at the same time carefully listening to the ideas of others.
I am shocked by his passing and offer my greatest condolences to Suzanne and the rest of his family.