why we have ".com", ".edu", ".org", and ".net" -- and a whole lot more, now. I worked for the very first .com company -- Symbolics.com -- when DNS was first instituted. Before that, host names were things like MIT-AI (the MIT AI lab) or SAIL (The Stanford AI lab), each naming a specific machine (with aliases) at a specific network address, rather than based on organization. So you had to know specifically which system your recipient received his mail on, though usually there were suitable forwardings for most people. Now, with DNS and MX records, it's decoupled from what systems actually handle the email, and often it's not even a system operated by the recipient's organization (perhaps, say, Google). There were a lot of arguments about whether names should be like they were in UUCP -- from less specific to more -- or as we ended up going with -- from more specific to less. We could have had com.google instead of google.com! (For practical reasons, some applications that reuse domain names for other purposes, such as the Java programming language, do reverse them.). I think the telling argument may have been that UUCP wasn't really from more specific to less, but just better-connected to less-well-connected. And people really wanted to break from that mindset, and emphasize that these were names in a naming scheme, and not at all paths. There was another scheme used as well, using % instead of ! This wasn't a full path-based scheme, but a