Fast-Play Grande ArmÃ©e (FPGA) is a complete revision of the original game, streamlined and simplified so that a handful of people can play the very largest battle scenarios to completion in a few hours with virtually no paperwork. Some people consider it an "introductory" version of Grande ArmÃ©e, but in fact it has a number of different systems that are related to, or derived from "regular" GA, but are not the same.
FPGA does not use any unit rosters, and in fact base-labels are no longer necessary. That alone speeds set-up time tremendously. There are a number of other dramatic simplifications in movement, combat, and morale rules. The results are remarkable: I have hosted FPGA games at conventions, with 14 players - none of whom had ever played before - playing armies that represented a total of 350,000 men. In each case we played a game to a decisive conclusion in only four hours.
FPGA is not finished, nor will it ever be for sale. It is a continuous work-in-progress, available for free at this site. Players in the future will contribute scenarios especially for FPGA, and I will return from time to time with updates, and possibly a campaign system and/or points-based "pick-up game" army list.