The "cool URLs" idea doesn't (AFAIK) cover mutability and temporal issues. In 1998, "yahoo.com" referred to the homepage of Yahoo!. In 2016, "yahoo.com" still

The "cool URLs" idea doesn't (AFAIK) cover mutability and temporal issues. In 1998, "yahoo.com" referred to the homepage of Yahoo!. In 2016, "yahoo.com" still refers to the homepage of Yahoo!. The content of the page isn't the same, but it's still the same 'entity' (the homepage of Yahoo!). Hence, despite Yahoo! being uncool, and the contents of the Yahoo! homepage being uncool, the URL of the Yahoo! homepage is cool. It would be nice if URLs had a built-in capability to reference immutable versions of things, similar to git references. This is done on niche networks like IPFS (I think) and Freenet. It's easy to imagine a DNS-like layer which sends "pet names" like "yahoo.com" to the latest version, whilst leaving "raw" names alone (like DNS does for IP addresses). With that said, it would also be nice if DOM elements got their own URLs which user agents could load instead of the whole page (imagine anchors but using something like XPath). That would make hyperlinks more useful and bring us a step closer to Xanadu-like behaviour, e.g. rather than copying text from a page and wrapping it in quotation marks, you could embed that element inside (a quotation element inside) your page.