.MX File Extension
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File TypeMathematica Serialized Package File
Developer  Wolfram Research 
Popularity  
Category  Data Files 
Format  Binary
BinaryThis file is saved in a binary format, which requires a specific program to read its contents. 
Binary package created by Mathematica, a desktop application used for computation and visualization; stores Mathematica expressions in a proprietary serialized format, which is optimized for fast loading; used for distributing Mathematica packages.
Mathematica packages can be created using DumpSave and read using Get. They can also be imported using the Import command and exported using the Export command. For example, Import["myFile.mx"] reads the MX file and returns an expression. Similarly, Export["myFile.mx", expr] serializes the "expr" expression and saves it to an MX file.
Since MX files are saved in a binary format, they are nonhuman readable. Additionally, they cannot be shared between different versions of Mathematica or between installations of Mathematica on different operating systems.
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