Why I need more than one OS (and machine) in general

• While I prefer to develop software in UNIX-style environments, there are still companies that provide product-support software for Windows only.

• I have had many instances where a problem on one system is easily bypassed on the other system.

• It is good education for a ``software engineer'' or ``computer hobbyist'' to keep up with the leading operating systems and user software.

• All machines get busy once in a while, and instead of staring at an hourglass or beachball cursor, it's great to be able to pop over to another machine that's idle. One's tablet and/or smartphone can similarly be used on the road as a ``something-to-do computer'' while waiting for a laptop to come back.