Competition like that helps the consumer (as in, us, the people using the software) and gives us better products. So long story short, Microsoft undoubtedly got ideas from Apple. Apple undoubtedly got ideas from Microsoft. Both of them undoubtedly saw things done in other OS projects and adopted those ideas as well. Microsoft obviously did it better than anyone else, and their operating system is now the dominant one on the planet (something like 90% of ALL computers use Windows). What's important is that without the competition, we probably wouldn't have anything like what we have now. It drives sales, development, creativity, ideas, etc.