GDevelop is an open source game creation software.

LÖVE is a framework you can use to make 2D games in Lua.

001 Game Creator is a graphically assisted scripting engine.

Heroic Labs is an open-source realtime server for apps and games.

Construct 3 is a game making software to develop and build games.

Playir is a mobile app and game creation platform, that allows you to create your own games and apps from pre-made templates.

libGDX is a free and open-source game-development application framework.