XnGine (or X-ngine) is a DOS based 3D engine developed by Bethesda Softworks. Bethesda used the engine for several games released between 1995 and 1999.
XnGine was developed by Bethesda Softworks in 1995. Bethesda has invested over $3 million and nine man-years in continued development of the engine. ' was the first game to use the engine, and also the first 3D PC game to use the now popular mouse-look interface, which was initially unpopular with gamers.
XnGine incorporated technology advances that made games more realistic. The engine featured quicker action, unrestricted viewing angles and freedom of movement. Its proprietary technology integrates 360-degree rotation with fully textured polygons, SVGA/VGA graphics and specialized video effects. XnGine can generate weather effects, such as snow, sleet and fog; realistic shading; and textured, contoured terrain. In an Interview with PCM&E Magazine in 1996, Todd Howard described the engine as a true 3D engine that delivered above any other engine in its lighting in that it uses real-time phong shading, which means that light effects from fires, explosions, the moon, or whatever will bleed off and light up anything the light will touch.
With ', support was implemented for 3D graphics cards equipped with 3dfx graphics processors. Competing technologies from Matrox and Nvidia were not supported.
With the release of Battlespire, GameSpot wrote the following regarding the engine: