ramin_hal9001, Bonfire: a general #ActivityPub server with pluggable front-end modules
...and it is programmed in Elixer!!! This typed programming language that runs on the Erlang platform automatically gives it a powerful advantage over more mainstream programming languages like Go or Ruby, through type safety and a language runtime that is built from the ground-up to be massively parallelizable and upward scalable, and easy to debug and patch running systems without downtime.
But from an end-user perspective, this is a social network framework in which you can install whatever front-end features you want through pluggable modules. If you want a Mastodon-like module, install that, if you want a Lemmy-like, or a Pixelfed-like, or a Frendica-like, you can theoretically just plug those in as well. From administrative tools to search and post indexing to social graph analysis, there are as many as 75 currently listed plug-ins. For anyone interested in #fediverse technology, this is definitely a project to watch, and possibly even to which to contribute.
See also this article by Sean Tilly.