Rated 5 out of 5 stars

by diyWorks on March 24, 2011 · permalink

1. Install the following addon: https://addons.mozilla.org/en-US/firefox/addon/au-english-dictionary/
2. Goto: about:config
3. Goto: layout.spellcheckDefault and change the value to 2. Restart Firefox.

This will make the dictionary available for every Firefox profile. For some reason you need to make layout.spellcheckDefault=2 to make Firefox remember the dictionary.