Stratagus

Stratagus is a free and open-source cross-platform game engine used to create real-time strategy (RTS) games. It is designed to be highly flexible and customizable, allowing developers to create games with varying rulesets, graphics, and gameplay styles. The engine handles core RTS game mechanics such as unit management, resource gathering, building construction, and combat.

Originally known as Freeciv, Stratagus was initially developed to create a clone of the popular Civilization series. However, its scope was expanded to encompass a more general-purpose RTS engine. The name "Stratagus" reflects this expanded focus on strategy games in general.

Stratagus itself does not include any specific game content. Instead, it provides the underlying engine and tools necessary for developers to build and distribute their own games using the engine. This allows for a thriving community of developers creating games based on Stratagus. These games often feature original artwork, sound, and storylines.

A key feature of Stratagus is its scripting capabilities. Developers can use Lua scripting to customize game behavior, add new units and buildings, and implement complex AI strategies. This allows for a high degree of moddability and customization.

The engine is written primarily in C++ and is licensed under the GNU General Public License (GPL), making it free to use, distribute, and modify. This open-source nature has contributed to its longevity and the continued development efforts of the Stratagus community.