Littr.me is a minimalist link aggregator inspired by (old)reddit using ActivityPub federation.
It is free software and released under the MIT license.
The code resides on Github for the moment.
The main difference from the other link aggregators is that it doesn’t use subcategories for separating user’s interests, but considers every instance the equivalent of such a subcategory. Ideally, this means that every instance will be small, focused on a well defined interest group.
Another important fact is that littr.me doesn’t use any other API for communication between its frontend and its ActivityPub backend, making it one of the few client to server implementors of ActivityPub.