OpenReview has: - preprints - versioning - reviewing, with threads and latex support - ability to link websites, repos, datasets, etc - bibtex generation
But it's not as popular as arxiv, though very popular in review (conferences often do not use full features)
One thing I dislike about this is that it is open to all. Arxiv doesn't have a hard filter (you just need someone with an account to vet you, which stakes their reputation), but the existence of a filter is critical.
I don't want a place to engage with the public. We have Reddit, hacker news, Twitter, mastodon, and countless other places. I want a place for academics to talk to academics [0], researchers to researchers. There is a serious lack of spaces where serious low level in-the-weeds discussions can happen. Even fucking GitHub and hugging face are swamped by people asking dumb questions on research projects like how to install pytorch, fine tune a model, or where the source code is.
I'm really happy to include a lot of people, but I think we also need spaces where experts know they're talking to peers. Without that you have to assume you're not talking to peers because they outnumber us a few thousand to one. So that doesn't encourage engaging in research or technical discussions, it encourages talking down to peers and misinterpreting.
[0] a degree is not what makes you "an academic"