Morningstar held many jobs throughout his career in the research and development of technology and programs. Most notably was Morningstar's role as project leader for Lucasfilm's "Habitat", the first large-scale virtual multiuser environment. In March 2001, Morningstar and colleague Randy Farmer were awarded the inaugural "First Penguin Award" by the International Game Developers Association for their work on Habitat. He also participated in Project Xanadu, for which the word hypertext was first coined. Additionally, he is credited with coining the term avatar and pre-Internet work in online information marketplaces.