I don’t see any option yet. Has this progressed?
AI-generated summary
The discussion revolves around adding Libravatar support to Discourse as a free and open-source alternative to Gravatar. Dave Lane proposed enabling users to swap Gravatar’s URL for Libravatar’s via admin settings, noting Libravatar’s API compatibility and ease of migration. Sam Saffron supported making core more extensible for such features via plugins, encouraging a pull request. Later, Falco confirmed that a site setting called gravatar base url already exists, allowing administrators to point to Libravatar’s URL (e.g., https://libravatar.org). rokejulianlockhart requested confirmation and documentation, and Falco invited testing. The thread then shifted to whether the Q&A plugin should be enabled for marking solutions — JammyDodger suggested moving the topic to Product Support to use the Solution button, which rokejulianlockhart agreed with, adding a preference for the plugin to be enabled across all categories. JammyDodger explained that while it’s active in support-focused categories, it’s intentionally omitted from more discursive ones — highlighting Discourse’s flexibility to adapt to different forum styles.
Yes, there is a site setting for gravatar base url.
So has this been implemented, then, @Falco? If so, please set it as Topics tagged solved or direct me to where how to is documented, because I don’t know how to.
Yes, please give it a try and let us know how it goes.
Do you have the Q&A plugin installed, @Falco? I’d like to mark that as the answer to the OP.
Not in the Contribute > Feature category.
As the feature already seems to exist, shall we slide this over to Support so we can make use of the Solution button? 
Yes, @JammyDodger, but it would also be great if the plugin were enabled in all categories. I find that it works best like that on other Discourse instances.
We have it enabled on a lot of our question/support categories, but don’t feel the need to turn it on for more discursive categories where there may not be ‘one right answer’. Though other forums may use it to good effect for similar things. That’s the beauty of Discourse, it’s incredibly versatile and can be tailored to suit different forum styles very easily. 