What is a MUI file
MUI is multilingual user interface. Windows uses the .MUI file to change the language interface. Microsoft windows uses it to display the text in multi languages.
This is a system resource file and contains the complete information for multilanguage version.
The mui files allows Windows interface to be changed to different languages.
Most additional languages packs can also be installed using the Muisetup.exe application.
It is used by Microsoft software and should not be opened manually.
This file is important for changing the language version. It is done for Windows interface when different versions are to be seen on the same Windows.
These .mui files can be used when multiple users having different languages use the system
There is no point in edit or view these kind of files as they are system type. However you can try an universal file opener or viewer to do it.
What Programs can Open it
Open with Windows:
This file is a Windows Multilanguage version resource. There is not any specific software or app.
Open with Linux: N.A.
MUI files contain resources by Windows 2000/XP Multilanguage version. They can change the Windows interface to multiple languages.
Ensure you associate the .MUI file extension with the Windows Multilanguage software.
How to create
You can use the Open GL toolkit to create it.
Windows also create this file type for language resources.