> Would a single operating system been a more productive use of developer time?
Yes, but a runner-up would be operating systems that can use each other's code, as is often the case with *nix-like operating systems. Given the natural tendency to fork operating systems, at least there's a way to cross-port code that works in most cases.
Oh -- I just realized you're asking this from an individual perspective. The answer is still yes -- you're better off focusing your attention on one OS. If you don't, you'll be competing with people who do, and they'll be more productive.
Yes, but a runner-up would be operating systems that can use each other's code, as is often the case with *nix-like operating systems. Given the natural tendency to fork operating systems, at least there's a way to cross-port code that works in most cases.
Oh -- I just realized you're asking this from an individual perspective. The answer is still yes -- you're better off focusing your attention on one OS. If you don't, you'll be competing with people who do, and they'll be more productive.