Lemmy: Oldest federated link aggregator, better documentation compared to Kbin, easy to self-deploy, less resource consumption, provides the most similar experience to Reddit

Kbin: Poorer documentation, no API access yet, harder to self-deploy, terminology and UI differences from Reddit can turn people off (I really don’t like “magazine” for a community)

Tildes: Centralized, invite-only and elitist. Not comparable to Lemmy and Kbin