@Edent Aye, there aren't any really big sites using @libravatar, though there are a few bits of software that support replacing their Gravatar URL with a custom one, so you could replace it with a service that knows how to look up using Libravatar's DNS protocol.

Though that's a far cry from being a native/integrated feature. I'm hoping an HTTP based protocol like you're suggesting could draw in more interest.

@nogweii @Edent There are some bigger sites that use Libravatar, but we‘re not bragging with it, not do we disclose that information. We‘re a bunch of people running the site for non-profite with a privacy-first approach (probably way better than Gravatar!).
The only site that I can talk about is Fedora and it‘s whole ecosystem that has Libravatar integrated even with OpenID (also used for lookup).

And I‘m open for suggestions about additional features!

@Edent @libravatar I agree. If there were a list of notable projects using Libravatar it becomes a useful tool for convincing other projects to adopt it as well. And that can become a snowball effect, accelerating adoption.

I'd love for Libravatar to become a de-facto thing to consider fetching avatars from, like Gravatar is, but it won't happen without advertising!