There are 2 file types use the .X file extension:
1. DirectX Model File
3D image file used by DirectX technology, which is often used for rendering 3D graphics in games; may contain specifications for meshes, textures, animations, and objects; can be exported using the DirectX SDK plugins for 3ds Max and Maya, or with custom exporters for programs such as Blender and DeleD.
|Microsoft DirectX SDK||Free|
Updated: November 22, 2011
2. Lex Source Code File
Source code written in the Lex programming language (a standard lexical analyzer for Unix); may be processed with the lex utility included with most Unix distributions to generate a C program; the output is often written to a file named "lex.yy.c."
Lex source code files more often use the .L extension.
Updated: June 10, 2011