(In the "I will add it to wiki later once I am an export but feel free to do it yourself now" departement)
Many applications (most importantly browsers in my case) use xdg-open to determine what application should be used to open certain file types.
/usr/share/applications/mimeinfo.cache contains a cache of what applications do support what mimetypes. Use /usr/share/applications/defaults.list to specify which applications you want to actually use for a given type. The following example will already go a long way:
[Default Applications] text/plain=emacsclient.desktop
(Unfortunately you will have add definitions to defaults.list even for types for which only one application has announced that it supports it. This is at least the case if xdg-open uses internal code to determine the appropriate application, if you use a desktop environment this might not be necessary.)
Unless you use firefox as your main browser you should also:
Now chromium will stop opening firefox for all types that are not configured in defaults.list.
As always there is additional information on the Arch wiki.
Last edited by tarsius (2011-02-02 12:27:35)