Wesnoth

TripleA is a turn based strategy game and board game engine, similar to Axis & Allies or Risk.

C # Game Framework, but not limited to games. Can be used for non game business development

RPG game action-adventure MMO built with Godot and Rust.

The automation tower defense RTS

Open-source, cross-platform 2D/3D/multiplayer game engine designed for everyone.

Desktop/Android/HTML5/iOS Java game development framework