I was going to blog about SYSVARS, a routine I wrote which lists all the SYStem VARiable information available in MVS when I realized I didn't have an example of the output. Bummer! So I went on the web to see if there was anything like a manual that would describe the output in a way I could use. I found, instead, (really... how could I forget?) David Alcock's MVS freeware page. Not only does it have screenshots of the output, but his code is probably better than mine, anyway.
Why have SYSVAR at all since all it does is display stuff you have no control over? When you're writing code and you need a quick reference, nothing beats being able to see the actual values that will be delivered by a SYSVAR call. Alternatively, when your SYSVAR call isn't working exactly the way you thought it would, you can quickly check that what's being returned is (or isn't) what you thought.
Little utility/demonstrator programs like SYSVAR can save precious time when you don't have much of it to waste — that's 'all the time' for most of us. You could do worse than to collect a toolbox-full of such things.