A MAC file contains a macro, which may be created by various programs, such as UltraEdit, Minitab, and Cabrilog Cabri Geometry II. It contains a list of commands in plain text that are used to perform functions in the respective application. MAC files can be opened by the programs that created them.

Macros are especially helpful for automating repetitive tasks. Users can record various types of functions, whether it be inserting a snippet of information, performing edits to an image, or calculating an equation, then execute them at a later time with just a couple mouse clicks or key combination. When saving a recorded function, the MAC file is created to store the commands that were performed to complete the function. The commands are stored in plain text in the MAC file and can be opened and edited by a text editor. However, a macro stored in a MAC file can only be executed by the program used to create it. NOTE: MAC files are potentially dangerous files because they may be used to store malware. It is important that you verify the source of a MAC file before opening it.