What is ET: Legacy and Legacy? - ET-Legacy-Competitive/faq GitHub Wiki

ET: Legacy is an open source project based on the code of Wolfenstein: Enemy Territory which was released in 2010 under the terms of the GPLv3.

Download link: https://etlegacy.com/

There are two aspects to this project:

An updated GAME ENGINE, ET: Legacy, which aims to fix bugs and security exploits, remove old dependencies, add useful features and modernize its graphics while still remaining compatible with ET 2.60b and as many of its mods as possible. What can you expect from the modernized engine:

an easy to run installer to get you in battle in no time;
nearly all known security issues and exploits fixed;
a clean, optimized code;
a fast, built-in minimizer;
all known security fixes.

While ET: Legacy is aiming to remain backwards compatible with ET 2.60b, do note that it's not compatible with ETPro mod, meaning you can not connect to ETPro servers with ET: Legacy client.

A new MOD, Legacy, which aims to add many useful features and improvements while staying close to the original gameplay, as well as being lightweight and extensible through Lua scripts.

The Legacy mod is the default mod shipped with ET: Legacy. It aims to:

fix vanilla bugs;
add useful features and improvements while staying close to the original gameplay;
stay lightweight and be extensible through Lua scripts;
be a viable and up-to-date alternative to the popular ETPro mod - just plain and pure ET experience.

Credits: ET: Legacy Wiki, which you can find here: https://github.com/etlegacy/etlegacy/wiki/About