Over deze add-on
Norwegian nynorsk dictionary for Mozilla Firefox, Mozilla Thunderbird and SeaMonkey.
Note: This is a dictonary for the built-in spellchecker and not a dictonary used for translation. This extension is put in the Dictionary section so that it could be included on the Dictionaries & Language Packs page. (https://addons.mozilla.org/en-US/firefox/browse/type:3).
This dictionary is based on the Spell-norwegian project available at http://no.speling.org/, and it's the same dictionary used in e.g. OpenOffice.org and some other OpenSource projects.