Having not lived the days of yore, I'm guessing that there were inferior mail clients that came before pine that are now long-forgotten because pine was better. Gmail is a similarly superior online email; it may not be the first, but it's the best, and that's all anyone remembers.
Yes, ecuzzillo said exactly what I meant. I also remember reading that Gmail consciously adopted Pine keyboard shortcuts (though I may have that wrong), which is why I made the direct link. Gmail seems like a very UNIX-y web mail client, where Hotmail, say, was not.
yah I'm a dork