Nothing annoys me quite like linux and using OSS tools

[KevinM1]

I guess I just don't understand why the distros make such a difference. I get that there are several main branches/versions of linux (Debian, Red Hat, etc.), but it just seems... well, dumb, that every flavor based on those would vary significantly enough to warrant such integration testing. It seems needlessly fragmented from my POV.

And should the LAMP stack be considered system tools? Real question, not a rhetorical device. They just seem like software to me. Apache is a web server. PHP is a specialized module for that web server. MySQL is a database. From a end user POV, I don't see why they'd require so much testing. They don't seem to interact with linux itself beyond the scope of, say, Firefox. Clarification would be greatly appreciated there.

I'm entirely self-taught, so I'm no doubt missing critical information, which is why things can quickly get frustrating. Unfortunately, I haven't found a good, modern "Here's what you need to know about linux from the ground up" resource. Everything I've found assumes a level of knowledge I don't possess.

EDIT: I guess I'm trying to fathom the why of linux. Because it seems more reasonable to have a singular core kernel that productivity software like the LAMP stack can target so it's universal across distros.