CAD project file created by Multisim, a circuit design, analysis, and simulation program; contains references to one or more circuit designs, which are stored in .MS11 files; may also contain simulation results, documents, and reports; used for organizing and managing multiple designs in a project.

NOTE: Each version of Multisim uses an extension that includes the version number. For example, Multisim version 10 uses the .MP10 extension.