Yesterday I wrote the idea "small pieces loosely joined" was central to what we mean by the web.

Now I'd like to add another criteria. "All parts are replaceable." I think it's self-evident what it means. And of course there is no such thing, but the internet itself comes very close to this ideal.

Somewhere there has to be a naming authority that can turn a string of characters like "scripting.com" into a physical address that a machine can understand, like: "16.15.217.109." In all likelihood, the machine your browser gets the answer from is replaceable, and maybe even the machine it gets the information from, but at the end of the chain of machines that cache the result, is the authority for the .com TLD. That authority should do as little as it possibly can. For .com, the authority is Verisign, and actually that server doesn't return the address of scripting.com, it returns the address of the authority for that domain and for scripting.com that is hover.com, where I have registered the domain.

This means there is one tiny little part of the internet that is not replaceable. In creating software "of the web" it should follow suit.