In case you missed it, the lead developer of open federated Reddit-alternative @prismo has put up a new flagship instance:
This replaces the previous instance (prismo.news) which suffered a major database failure.
You'll have to sign up if you want to post or upvote, but you can follow users and comment on posts from elsewhere on the Fediverse.
An interesting feature of notabug is that it prevents spam via a Proof-of-Work algorithm. Submitting new stories and voting are both limited on the client side by CPU bound computation.
I wonder if the Fediverse has anything to learn from this model.
mastodon.at is a microblogging site that federates with most instances on the Fediverse.