The Guild was the second mental-physical training school see Bene Gesserit) after the ButlerianJihad.
The Guild monopoly on space travel and transport and upon internation al banking is taken as the beginning point of the Imperial Calendar.
In response to the strict Butlerian taboo against machines that perform mental functions, a number of schools developed enhanced human beings to subsume most of the functions formerly performed by computers.
Frank Herbert did indeed have rather concrete plans to write a seventh book just before his death in 1986.
Looking at the time-line found in the Dune Encyclopedia (which is considered to be non-canonical by Brain Herbert), I got some interesting ideas for the story about Holtzmann, a cyborged genius who after being 7487 years old was destroyed at the end of the ButlerianJihad.
This morning had a so-called "Town meeting" where the whole company comes together in the canteen to hear about the developments.
