Associating a File Extension with Oxygen XML Editor

To associate a file extension with Oxygen XML Editor on Windows:

Go to the Start menu and click Control Panel.
Go to Default Programs.
Click Associate a file type or protocol with a program.
Click the file extension you want to associate with Oxygen XML Editor, then click Change program.
In the Open With dialog box, click Browse and navigate to Oxygen XML Editor.

To associate a file extension with Oxygen XML Editor on Mac:

In Finder, right click a file and from the contextual menu select Get Info.
In the Open With subsection, select Other from the application combo and browse to Oxygen XML Editor.
With Oxygen XML Editor selected, click Change All.