War3Source brings the Warcraft 3 leveling style and races into the game. It is originally based on the amxmodx (AMX) version War3FT.
Each standard race has a total of 16 levels, made up of 3 skills and 1 ultimate where each skill/ultimate can be leveled 4 times for a total of 16 levels.
War3Source features a modular design where races can be coded independently and loaded into the main plugin. Independent plugins (Addons) can be created to complement or change aspects of War3Source.
There are also items in W3S as there are in all Warcraft mods.
War3Source is written in SourcePawn under the SourceMod extension.
Please note that the development of this plugin is inactive, and you may have better luck with War3Evo (links below).
This is a fork of War3: Source that is still actively developed. It is recommended that you try this, especially if the official version is giving you issues.