a128k21 is a Hungarian Minecraft Anarchy Survival server. It is a vanilla server with no plugins and only playable using Java Edition (at least for now, anyway). The server opened in 2019 and has been online and running ever since. When opened, it was on version 1.15 with a 1.13.2 map but has since been upgraded to 1.19.4. For players without a premium MC account, a128k21 also has an offline mode (aka cracked) version you can connect to (IP: cracked.a128k21.org).

Check out these awesome videos featuring a128k21:

https://youtu.be/r8D1WnZZFRM
(by Hero Warriors)

https://youtube.com/shorts/uq9FxxeQYOs
(by bangetto HUN)

https://youtu.be/7-1-u-awkIg
(by TheForgTN)