The format is actually ".po" and not ".mo".
.mo is in binary format, not used by Jubler, .po is in text.
So, it *is* in text format, as you asked

And so, as a text file, it's standard and universal.
The good thing with .po files is, next time you will need to translate newest version of Jubler, it is very easy to translate only the differences and not go through the whole translate file.
I've tried in my projects various translation mechanisms, and I strongly believe that gettext (the one with the .po files) is the best.
