Metal Gear Solid 2: Sons of Liberty (Japanese: メタルギアソリッド2　サンズ・オブ・リバティ) is an action-adventure stealth video game directed by Hideo Kojima, originally developed by Konami Computer Entertainment Japan and published by Konami for the PlayStation 2 in 2001. It is the fourth Metal Gear game produced and directed by Kojima and the direct sequel to Metal Gear Solid. Its release was followed by an expanded edition, Metal Gear Solid 2: Substance for Xbox, PlayStation 2 and Microsoft Windows.