Nah that's the current one. Version 1.4. There's also a thread up here for it. I'd been dragging my feet on updating it, but it's in process now, also going to get a website up for it. >>1665340>>1665523
So the use of the term originated in Roadside Picnic, but then liquidators at the Chernobyl zone itself who had read the story started referring to themselves as stalkers because of the unseen dangers (i.e. ball-frying levels of radiation). Then we got the movie Stalker, which reinforced the entire notion of the Zone and people in the Zone being known as Stalkers. Where it entered the imageboard mainstream was in the S.T.A.L.K.E.R. series of games, which were from a Ukranian studio, set in an alt-history version of the Chernobyl zone, and wherein anyone exploring or living in the Zone is known as a stalker.
The game's atmosphere, solid gunplay, and slavic themes made it a huge hit with /k/ in the early 2010s. For perspective - that was an era where $100 Mosin Nagants, $200 SKSs, and $600 AKs combined with the fact that AR-15s were close to $1k. Since most of /k/ is poor, they were buying eastern bloc guns, and slavshit turned into this massive meme (pic related), that then resulted in even more people buying slavshit.
Meanwhile, the game S.T.A.L.K.E.R. is still going strong for its age. The engine source code got leaked along with all of the unreleased beta maps, the modding scene is chugging away like mad, and there's been a general up on /vg/ ever since /vg/ was created. The HBO miniseries helped some zoomers discover it, too.