I have summarized the history of Post Publication Peer Review starting with Pubmed Commons to the leading website PubPeer. But most recently there are at least three new kids on the block: Peer Community In, Paperstars and alphaXiv.
What is the difference?
Peer Community In was founded in 2017 by Denis Bourguet and colleagues, targeting researchers across disciplines with a focus on peer-reviewing and recommending preprints as an alternative to traditional journals.
Paperstars, launched in 2023 by currently undisclosed founders, is aimed at both the general public and researchers, focusing on making scientific papers more accessible through AI-generated summaries and visuals.
alphaXiv was created in 2024 by the Allen Institute for AI to serve researchers and academics by enhancing preprint discoverability through AI-powered search and summarization tools.
BTW Science Guardians is a scammer website.