1. A method of cooperatively programming a simulation program of a computer application to be developed, the method comprising: communicating with a plurality of user computers, where the user computers display an executable simulation model of the simulation program of the computer application to be developed; permitting the user computers to simultaneously modify the executable simulation model thereby revising the simulation program of the computer application to be developed; receiving a modification to the executable simulation model from a first user computer selected from the user computers; and automatically providing an update to the plurality of user computers such that the plurality of user computers display the revised executable simulation model.