And frustrating for anyone with extensive experience with modern software stacks. The zseries is a strange combination of semi-modern hardware with ancient soft

And frustrating for anyone with extensive experience with modern software stacks. The zseries is a strange combination of semi-modern hardware with ancient software/hardware practices. I spent a year of my life with a recent mainframe as part of my previous job. During that time I discovered a long list of things that are frankly unbelievable to anyone familiar with modern computing. I should write a book about all the crazy crap, but I don't really have too. Just reading the install/setup/operating guides with a mainframe in hand should be sufficient for anyone with a clue. Bonus points if you install any industry standard benchmarks to measure things like memory/disk io/networking latency/bandwidth. But, in the end I get it. People talk about all kinds of crap that isn't true about the mainframe, but that doesn't matter. What companies are getting when they buy a zeries from IBM is a software stack with a 99.99% future compatibility statement. That means the millions you invest in developing software today will still work two decades from now. IBM isn't going to pull the rug out from under you when the latest OS/language/etc shows up. That is why its possible to run JCL/COBOL/etc written decades ago without change on modern machines. For companies that use computers to assist their main line of business (rather than being the main line itself) this is an extremely valuable feature.