WELCOME to ArmStalker Online! The Team has been working on this project since the days of Arma 2 - for years they have wanted to bring a truly live multiplayer sandbox experience to the universe of Stalker
From the Developers themselves (from their New Year 2017 address on vk.com):
"Friends as we often note... ...for many years burning the idea of creating a live anomalous zone, where every stalker, will be a living person, everything that happens, happens in the present, instead of the planned plot... Where we will have a chance to test ourselves in the real world, where it will be possible to be challenged, to check if you can become a master stalker from a novice-dumpling... A Legend woven throughout tales told at the hobo-campfire..."
There is much more general information about this large-scale modification for Arma 3 to be found at these links:
About the "Creator" of the Moddb page:
I am Uncle Boom. My Official title is "Foreign Representative", Public Relations for ArmStalker Developers and Community, bring information and direct communication to English speaking fans of the project worldwide. I am largely credited as being the first western player to play on the server... While I may be the first English-only American player to go talk to the Russian speaking players on the old WarZone PvP server - I know for a fact that I was not the first American to play on the server . Ultimately, who I am is not important beyond my recognized enthusiasm and understanding of the project. The fact is, I never hear anyone speak in English about ArmStalker without wanting to correct some small detail or finish a sentence... I have been following this project rabidly since I first heard of it in October 2015, and I have been lucky enough to strike up a friendship with some group players and at least one administrator/rp curator. I have learned a lot about the direction of the project over the last year, and I work on learning to understand Russian language everyday to help my efforts. I host the Official ArmStalker Group on Facebook where I catalog everything I can about the project, making sometimes too many posts in a day....
This project is something special to me, the players even more so, the friends I have made in the zone - More important to me than all of it... I am honored to be your host, and I hope I do a good job sharing what I know with you guys. If I don't know the answer to a specific question, I will tell you, and I know people who can certainly answer the question - so you can have confidence in what I tell you that I do know.
Good Hunting Everyone! More news and posts coming soon!