ChromieCraft

Type: World of Warcraft Private Server
Website: chromiecraft.com
Tagline: Progressive server powered by AzerothCore

ChromieCraft exists to improve AzerothCore, and the server is the test bed. It is a non-profit project run by the AzerothCore team itself, where every bug reported in game and every fix made is contributed back upstream to the open-source emulator that dozens of other servers run on. The gameplay model follows from that purpose rather than from marketing: content is released in phases tied to rising level caps, starting at 19, then 29, then 39, so each tier of the game gets played, broken and fixed in order. It holds a 24 hour peak of 5,361 online across a Discord of 20,613 members, one of the largest active populations in this directory.

Client: Wrath of the Lich King 3.3.5a
Progression: Phased level caps from 19 upward, running through Vanilla, The Burning Crusade and into Wrath
Type: Progressive PvE, open source, non-profit
Emulator: AzerothCore

EXP Rate: x2 during Vanilla-era phases
Rested EXP: Recruit-a-Friend grants permanent rested experience

Phased Level Caps: Content unlocks in steps at 19, 29, 39 and upward rather than the world opening fully at once, which gives every tier a real lifespan.
Fixes Go Upstream: Every bug report and fix feeds directly into AzerothCore, so playing here improves the emulator other servers depend on.
Non-Profit: 100% of donations are reinvested into development, hosting and advertising. There is no pay-to-win store and no gear sold.
Rescaled Vanilla Raids: Vanilla raids are resized for era-appropriate group sizes rather than run at their original headcounts.
Mythic-Style TBC Raids: Burning Crusade raids carry custom challenge modes above their standard difficulty.
Challenge Modes: Optional Hardcore, Ironman and Bloodthirsty modes for players wanting a punishing run. These require a custom client patch.
Cross-Faction Play: Parties, guilds and chat all work across factions from the start.
Battleground Levelling: Boosted battleground experience makes PvP a fully viable alternative levelling path.
Volunteer Staffed: The server is run by volunteers, with the stated philosophy being anti-commercial.
Standard Client: Runs on the ordinary 3.3.5a client, so no special download is needed to play.

Active Players: 5,361 peak online in the last 24 hours
Discord Community: 20,613 members