RPGBoss!

Godot is a fully featured, open source, MIT licensed game engine. It focuses on having great tools, and a visual oriented workflow that can export to PC, Mobile and Web platforms. It is a cross-platform 2D and 3D game engine and game development IDE.

Adventure Game Studio provides the tools to make your own adventure, for free! Bring your story and artwork and slot it in, and let AGS do the rest.

Open RPG Maker is a free and open source clone of features from the RPG Maker series (i.e. rpgmaker200, rpgmaker2003, rpgmakerxp), as well as many other features. All of the data files are in XML format and are easily editable with any text editor.

GameSalad Creator is an authoring tool developed by GameSalad, Inc. (formerly Gendai Games) aimed primarily at non-programmers for composing games in a drag-and-drop fashion, utilizing visual editors and a behavior-based logic system. It is used by consumers and creative professionals such as graphic designers, animators, and game developers for rapidly prototyping, building and self-publishing cross-platform games and interactive media. The application runs on Mac OS X and can produce iPhone , web browser-based content in HTML 5, and mac applications. »

Construct Classic is a free, DirectX 9 game creator for Windows, designed for 2D games. It uses an event based system for defining how the game behaves, in a visual, human-readable way - you dont need to program or script anything at all. Its intuitive for beginners, but powerful enough for advanced users to work without hindrance.

The RPG Toolkit is a free, open source project delivering a simple, flexible and powerful tool for the creation of role-playing games on your personal computer.

Bring your game ideas and concepts to life with 001 Game Creator, which gives you the power to create a variety of game genres. With simple point-and-click scripting, and high customisability of characters, monsters, items and magic, you can make anything possible. Will soon support mobile platforms.

Create your own mobile apps & 3D multiplayer games with our super-easy design tools for iOS, Android, Windows Phone and HTML5! Less programming, more playing.

Game Editor is the open source game design software that gives you the power to create the games of your dreams, and, unlike other game creation tools, gives you the chance to get and change the source code of the game creator and design and develop 2D games for iPhone, iPad, Mac OS X, Windows, Linux, Pocket PC, Windows Mobile, Windows Mobile-based Smartphones and GP2X.

Solarus is a free and open-source Action-RPG game engine, licensed under GPL, and written in C++. It runs quests in Lua, and can work on a great number of platforms. Solarus also features a game editor called Solarus Quest Editor, written in C++ with Qt to help you creating your game.

Game Character Hub is an art program that is focused on game asset creation, especially RPG Maker's. It provides a built-in generator for character and tileset creation.

EasyRPG is a project aimed at producing a free and open source role playing game interpreter and editor compatible with RPG Maker 2000 and 2003.

The G3D Innovation Engine is a commercial-grade C++ 3D engine available as Open Source (BSD License). It is used in commercial games, research papers, military simulators, and university courses. G3D supports hardware accelerated real-time rendering, off-line rendering like ray tracing, and general purpose computation on GPUs.

RPG Paper Maker is a free game maker engine including a 3D universe with many 2D sprites and some simplified 3D objects. Pretty close to the RPG Maker series, RPG Paper Maker finally give a way to create RPGs in a totally 3D universe as easy as it is in 2D!