STL (*.stl)
STL format is created by 3D Systems. This file format is supported by many other software packages. It is widely used for rapid prototyping with 3D printers and computer-aided manufacturing. STL files describe only the surface geometry of a three-dimensional object without any representation of color, texture or other common CAD model attributes. An STL file describes a raw unstructured triangulated surface.
STL file format
is simple and easy to output. Consequently, many computer-aided design systems can output the STL file format. STL can also be used for interchanging data between CAD/CAM systems and computational environments such as Mathematica.Source: wikipedia