OpenMW is an open-source open-world RPG game engine that supports playing Morrowind. Main repo and issue tracker can be found here: https://gitlab.com/OpenMW/openmw/

ScummVM main repository

Reimplementation of Gothic 2 Notr

RPG Maker 2000/2003 and EasyRPG games interpreter

Unreal Engine 4 Action RPG type game starter kit.

Retro RPG Game Maker

H2服务器引擎架构是轻量级的，与其说是引擎，个人觉得称之为平台更为合适。因为它封装的功能少之又少，但是提供了非常简洁方便的扩展机制，使得可以用C++、python、lua、js、php来开发具体的服务器功能。H2引擎的灵感来源于web服务器Apache。

An implementation of the Diablo 1 game engine

Scott's Open Source C# RPG

Modular game engine built with MonoGame, with GMS2-like workflow and advanced level editor

🎨: RPG map maker (paint tool)

Open Source role-playing game engine for Taleworlds' Mount&Blade Series written in C# using Ogre3d Engine

Official Hamster Republic RPG Construction Engine (mirror of SVN repository)

Old-school CRPG engine, editor and game

2D RPG Game creator

Script per la creazione di Giochi di Ruolo "Play by Chat" su browser

The version IDMarinas Edition is based on the version 1.1.2 Dragonprime by Dragonprime Development Team (Dragonprime) and have code of Oliver Brendel (NB Core).

2D Open world ascii rpg game written in Python 3, standard library

Js JRPG Engine for FGMK

A RPG Engine using JavaScript