An MXT file is a geographical map template created with the GIS mapping application, ArcMap that comes as part of ESRI ArcGIS Desktop. It is used to store basemap layers or page layouts that can be reused to create more maps. Using templates saves you time as you don’t have to reproduce the common parts of the maps. MXT files can be shared with other users/organizations to get to quickly build other maps.
MXT File Format
MXT files are saved as binary files but their internal file structure details are not available publicly for developer’s reference. It contains information such as the base properties of a map, layout positions, and visibility of application toolbars. MXT files enable users to create multiple maps with predefined settings already available to them.