I'm now using Ubuntu 12.04.
In earlier versions you could associate a filetype with a specific command (e.g. self-compiled binary) by selecting "Open with" in the file's properties and select the command by providing the file path manually if it wasn't already in the list of applications.
Is this possibility gone?
The only way I found now is to create .desktop files and edit the mimetypes via an text editor.
Best Answer
I think you are looking for an answer like this. A user has asked for help on how to open
fits
file type that is not supported by default ubuntu programs.IraGainesUK has posted the answer at http://ubuntuforums.org/showpost.php?p=12242314&postcount=5
I should note that I have tested the solution and it worked well for me.