Files with the MAS extension identify a stored procedure file created in the Microsoft Access application. MAS files store definitions and descriptions that are composed in Structured Query Language (SQL) that can be accessed by database applications. MAS files may be opened and edited using compatible database software applications.
File used by 3ds Max, a 3D modeling and animation software package; stores a material, which defines the way textures and lighting are applied to a surface; can be accessed from the Material Editor component in 3ds Max.