[Mailman-i18n] new translator guidelines; mailman.mo query

[Darren Wyn Rees]

Where is the most current guidelines on adding new translations to mailman ?

I could only find this :
http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/mailman/mailman/README-I18N.en?rev=2.0&content-type=text/vnd.viewcvs-markup

Assuming the above is still valid - please correct me if otherwise - I have
difficulty understanding :

    Once you've added your translations, you can then run msgfmt over
    your .po file to generate messages/ha/LC_MESSAGE/mailman.mo (it
    would also be a good idea to donate your translated .po file back
    to the Mailman project!)

(a) I can't find msgformat, and (b) I don't understand the purpose of this file.

Thanks for any help.

-- 
Darren