Spring is a project aiming to create a new and versatile RTS Engine. It features:
* Open source (GPLv2).
* Multi-plattform (Windows & Linux, MacOSX in progress).
* Written in C++, using OpenGL, OpenAL, FreeType2, DevIL, SDL, GLEW, boost, 7zip, Lua and streflop.
* Very extensive Lua interface, allowing gameplay changes and custom (G-)UIs.
* Large battles limited only by the power of your computer; support for up to 30000 units and up to 250 players.
* Full 3D combat in land, sea and air, with realistic weapon trajectories (physics simulation engine).
* Full featured lobby clients to easily play multiplayer games on LAN or online, with hundreds of players just waiting for you at any time. Including automatic game and map downloading, chat, friends list etc.
* Complex 3rd party Skirmish AIs (Bots), supporting special game types and many Spring games and mods. They can be coded in Lua, C, C++, Python, all JVM languages (eg. Java), and more languages can be added.
* Several camera modes, allowing for anything to be viewed from almost any angle.
* A powerful UI designed to minimize unnecessary micromanagement that is easily extensible via a Lua API.
* A lot of third party widgets to improve the GUI, the gameplay and the visuals.
* Many different Games, made just for Spring.
* Hundreds of large and highly detailed maps in which to wage those battles in full 3D, with deformable terrain, forest fires, dynamic and reflective bump mapped water, and custom skies.
(copied from wiki page)
this is a separate project built on the Spring-RTS project by Harvey Newell