eJourn doesn't do everything, and it never will. So, certain file types will always need other programs to be loaded in (and those programs are probably better at it anyway). So, fill in the programs here which you wish to use.
The program will likely default to my favorites otherwise: firefox, gqview, xine.
If you're unsure what to put here, and you're a Gnome user, go ahead and put gnome-open into all of them. (Ubuntu uses Gnome for example).