It can get quite annoying if for example you want to edit some code and end up opening Libre Office Word. To set the correct applications, we can use Preferred Applications in Ubuntu Mate. If your using a different Linux distribution / file / window manager the application will be different, but will follow the same procedure.
In the Ubuntu mate menu go to Preferences >> Preferred Applications
Or open your terminal and enter the following command
mate-default-applications-properties
Once opened setting the preferred / default application is pretty straightforward.
You can change the default applications for the following categories:
Web Browser
Mail Reader
Instant Messenger
Image Viewer
Multimedia Player
Video Player
Text Editor
Terminal Emulator
File Manager
Calculator
Document Viewer
Word Processor
Spreadsheet Editor
Visual
Mobility
