The game engine is free and open-source software, subject to the terms of the GNU General Public License v2.0 or later.
The development was initiated by Stefan Johansson, Tomaz Kunaver, and Jelmer Cnossen, members of the Swedish Yankspankers game clan under the name TA Spring.
Since then, the project evolved from a mere TA clone to a general RTS game engine including more flexible features like built-in high-level extensibility through a Lua scripting interface.
There are also currently a number of single player missions, built on frameworks utilizing the engine's Lua scripting abilities.
There are also a large number of skirmish artificial intelligences (AIs), allowing for offline play or extra players in an online game.
Most popular in this area are the "chicken" modes of Zero-K and Balanced Annihilation, where a player has to defend against waves of monsters.
Skirmish AIs (or bots) are needed to get a normal single player game running.
[4] Spring's source code,[5] licensed under the GNU GPL-2.0-or-later, is primarily written in the programming language C++, as is springlobby.
Among Spring games, Zero-K is notable for its extensive use of Lua scripting for interface and gameplay enhancements, and unique RTS concepts such as a flat technology tree.
[12][13] NOTA[14] (Not Original Total Annihilation) is a game designed for larger maps with to-scale units, fuel for airplanes and accent for strategic decisions.
It has a unique navy, more diversified unit types, and a slower tech/econ development then other TA themed games (BA, XTA).
This unique game is about an undead demonic army that corrupts the universe and is opposed by humankind.
The artistic setup is inspired by arts from Doom I and II, Warcraft III and Warhammer table tops.
[16] Spring:1944 is one of the most-developed games on the Spring engine, and as the name suggests is based on the later years of World War II.
It features all units from the retail version of Total Annihilation with a few additional ones added to each faction.
Spring was reviewed in French print computer magazine Linux Pratique in February 2009.