This addon allows you to look up an avatar image for new users and contacts at Libravatar. It will be used if there have not been found any other avatar images yet for example through OpenID.
Libravatar is a free and open replacement for Gravatar. It is a service where people can store an avatar image for their email-addresses. These avatar images can get looked up for example in comment functions, profile pages, etc. on other sites. There exists a central installation at www.libravatar.com, but you can also host it on your own server. If no avatar was found Libravatar will look up at Gravatar as a fallback. There is no rating available, as it is on Gravatar, so all avatar lookups are g-rated. (Suitable for all audiences.)
You can not use the Libravatar and Gravatar addon at the same time. You need to choose one. If you need other ratings than g you better stay with Gravatar, otherwise it is safe to use Libravatar, because it will fall back to Gravatar if nothing was found at Libravatar.
If no avatar was found for an email Libravatar can create some pseudo-random generated avatars based on an email hash. You can choose between these presets:
See examples at Libravatar.
config/local.config.php file and add "libravatar" to the list of activated addons:
'system' => [ ... 'addon' => '...,libravatar' ... ]
You can add one configuration variables for the addon to the
'libravatar' => [ 'default_avatar' => 'identicon', ],