Phil Karlton (SGI) initially proposed the server overlay visuals convention to the X Consortium. David Wiggins (Intergraph) contributed to the proposal. Todd Newman (SGI) did the first implementation of overlay visuals; Peter Daifuku (SGI) implemented SGI's current implementation for IRIX 5.0. John Marks (Hewlett-Packard) helped me ensure the example code worked on Hewlett-Packard workstations too.