TrinityCore Open Source MMO Framework (master = 11.0.5.57689, 3.3.5 = 3.3.5a.12340, cata classic = 4.4.1.57564)

Unity3D Client And C# Server Framework

Complete Open Source and Modular solution for MMO

A MMOG engine of server.

#1 Open Source Unity Networking Library

最全面的游戏开发技术图谱。帮助游戏开发者们在已知问题上节省时间，省出更多的精力投入到更有创造性的工作中去。

A fast, scalable, distributed game server engine/framework for C++, include the actor library, network library, can be used as a real time multiplayer game engine ( MMO RPG/MOBA ), which support C#/Lua script/ Unity3d, Cocos2dx and plan to support Unreal.

rAthena is an open-source cross-platform MMORPG server.

一个基于Entity-Component模式的灵活、通用、可扩展的轻量战斗（技能）框架，配置可选使用ScriptableObject或是Excel表格. A flexible, generic, easy to extend, lightweight combat (skills) framework based on Entity-Component pattern. Configuration can choose to use ScriptableObject or Excel tables.

A free and open-source MMORPG server emulator written in C++

游戏服务器框架，网络层分别用SocketAPI、Boost Asio、Libuv三种方式实现， 框架内使用共享内存，无锁队列，对象池，内存池来提高服务器性能。还包含一个不断完善的Unity 3D客户端，客户端含大量完整资源，坐骑，宠物，伙伴，装备, 这些均己实现上阵和穿戴, 并可进入副本战斗，多人玩法也己实现, 持续开发中。

Framework to create an RPG or MMORPG (with the same code) in the browser with Typescript

⚔️ An online JavaScript 2D Medieval RPG.

A free/open source client and automation tool for Ragnarok Online

Hercules is a collaborative software development project revolving around the creation of a robust massively multiplayer online role playing game (MMORPG) server package. Written in C, the program is very versatile and provides NPCs, warps and modifications. The project is jointly managed by a group of volunteers located around the world as well…

This project aims to create an easy to use, extendable and customizable server for a MMORPG called "MU Online".

An Ultima Online server emulator written in C# .NET

Stendhal is a fun friendly and free multiplayer online adventure game with an old school feel.

An emulator for the defunct MMORPG WildStar which supports build 16042 (Final Patch)

Easy to use high performance Network library for Unity 3d