One of the largest Vanilla World of Warcraft private servers. Kronos is part of the Twinstar system and has x1 blizzlike rates. They currently offer 2 realms, Kronos I and Kronos II. Kronos II is the newer realm and has the higher population. The server are being merged together some time in 2017.
Really solid server, I’m only up to level 43 on a warlock but it’s been great so far! I did have some issues with the pets glitching (screenshot attached). Support for the issue was pretty slow, but eventually another player showed me how to fix it.