So on the one hand, we're already supposed to have permanent identifiers, and they're called URIs/URLs.<p>On the other hand, what is it that makes URL's fail even if the content still exists on the web?<p>Generally, changes in platforms hosting the content, that addresses them differently.<p>It is not technically hard to provide redirection yourself that redirects from the old URLs to the new ones. If the new platform still uses the same internal identifiers for each piece of content, it may be as simple as a one-line apache httpd or nginx redirect, from `<a href="http://example.com/get/thing/$ID`" rel="nofollow">http://example.com/get/thing/$ID`</a> to `<a href="http://example.com/find/it/here/$ID`" rel="nofollow">http://example.com/find/it/here/$ID`</a> or whatever. If the internal identifiers have changed, it's a pain to list the mapping -- but that pain doesn't actually diminish much at all with this w3id.org service, you're still going to have to update all the URLs individually with their service.<p>Another possibility is that your hostname has changed; as long as you haven't lost the ownership of the old domain though, it is still not technically hard to point it to the same place as your new one, and then you're reduced to the same situation as above.<p>So it's not technically hard to provide the URL redirection yourself locally. If you want to provide your own platform-idenpendent "permanent identifiers" from the start, there's even several open source packages meant to help you do it yourself, locally.<p>On the other hand,it is another thing to think about, another thing to maintain and monitor. Nearly everything else one can think of, even things not that hard to do locally, especially if they might require running another service locally, is being 'outsourced' to "X As a Service" platforms.<p>So, okay, why not 'permanent' identifiers too? I wish people would just take care of it themselves, the way the web was intended. And I wish w3id.org actually just identified themselves as "permanent identifiers as a service" or whatever, instead of implying that they're doing something fundamentally different than plain old URL redirection you can do not too difficultly yourself.<p>And it is important to note that you are relying on the continued existence and maintenance of the w3id.org hostname and service behind it for "permanence". When "permanent" is in the name, the risks of relying on an "_ as a service" provider are higher, you can't really switch to a different provider later, you're stuck with them literally forever, and counting on them existing as long as you need your identifiers to.<p>But it's not too surprising if people are looking for "permanent identifiers as a service", they're looking for nearly everything as a service. On the other other hand, most entities don't seem to care about permanence in their URI's _at all_ -- if you are at the point where you realize it's important, I'd think you'd be the kind of entity to have the technical capacity to implement it yourself locally too, and then have true local control over the 'permanence' of identifiers, not have to rely on a third party continuing to be maintained.