Over on firstname.lastname@example.org we were talking about yet more extensions to the META.yml when Eric Wilhelm pointed out that there's no way to get at the meta data for your installed modules. The META.yml isn't stored anywhere. I sort of waved my hands around about someone making some sort of CPAN REST web service...
But wait, we have one. search.cpan.org has a REST API. You can do things like http://search.cpan.org/dist/Error and to get the META.yml http://search.cpan.org/meta/Error/META.yml http://search.cpan.org/meta/Error-0.13/META.yml.
That's great, but to do anything useful with this information on a web site we need JSON. I suggested it to Graham and he implemented it. http://search.cpan.org/meta/Error-0.13/META.json
Finally, there's one more bonus feature. See, Error.pm 0.13 doesn't ship with a META.yml file so search.cpan.org generates it! It fills in as much information it can including links to rt.cpan.org, CPAN Forum, CPAN Testers and search.cpan.org's own online diff and grep tools.
Now other web sites can get information about CPAN modules in two easy to swallow formats.