I agree with you, but let's be honest, if you aren't already well exposed to that world then those docs are going to scare the shit out of you. They definitely

I agree with you, but let's be honest, if you aren't already well exposed to that world then those docs are going to scare the shit out of you. They definitely are not "easy reads". The extent to which you are looking for something reference like and intensely technical vs. something to ease you into a new stack will determine whether you appreciate IBMs mainframe docs. They definitely don't fit the mold of what most people expect from documentation nowadays though. If anybody wants to see what they look like, type IBM zOS v2r5 indexed collection into Google (the most recent batch of docs). I don't really have any one in particular that I would recommend starting with, because none of it is going to make much sense if you are new to that world. The ABCs of Systems Programming Redbooks are probably a better introduction than the main documentation, although those volumes are a little bit more out of date.