In the latter half of the twentieth century, two of the highest-flying tech firms were Wang Laboratories, manufacturer of word processors, and Research in Motion (RIM), a Canadian company that produced the famed Blackberry, which took the world of cell phones and electronic email by storm. It’s instructive to look at the timeline of these two companies, both in terms of technology and revenues, to see how things can go very badly very quickly for a company operating in a fast-changing environment.