Like, the fash have Metapedia yeah? Wouldn't it be good to have a wiki that is a source of information from a leftist view. Particularly to counter common bullshit narratives that Wikipedia gives too much credence too? The Tiananmen square thread on the front page made me look up what Wikipedia has to say about it, and while its actually not as bad as I expected it definitely still has some liberalism.
Right now, as far as I am aware, the closest that exists is fucking Rationalwiki, which while their articles on social issues tend to be good (their article on Gamergate is a go to source for me lol) their articles on communism and anarchism are... again not as bad as you might expect but still pretty bad.
[I just realized it may end up being not as feasible as I'd hope because of leftist infighting about certain historical incidents lol, fuck]
Our comrades on lemmygrad are working on something like that called prolewiki.
Also a good project to work on, don't get me wrong, but I think having a central hub of leftist information to link people could also be useful.
Cuba has their own version of Wikipedia from a socialist perspective: https://www.ecured.cu/Estados_Unidos
You'll have to use a translator if you don't know Spanish though.
I think a Marxism Stack Exchange would be helpful too. It would be nice to generate a collection of definitive answers that we can link people to for all the 101 questions that get asked over and over again by baby lefts.
Being left wing is the rational position. Critical theory on power & society gets you there; many comrades also arrive from life-changing hurt that shatters the propaganda. So in that sense Wikipedia/RWiki already are leftist Wikipedia, lib as they are. There's a space for theory wikis, specialised for each tendency. Sorta like the Fandoms for TV & games.