NILHello !
Today I felt the need to change the language of my Firefox browser to
esperanto but I haven't been able to do this, it is not
straightforward...
First, you need to install your language pack, depending if you use
the official Mozilla Firefox or Icecat, the rebranded firefox with
non-free stuff removed
+ [link for Mozilla Firefox](https://addons.mozilla.org/en-US/firefox/language-tools/)
+ [link for Icecat](ftp://ftp.gnu.org/gnu/gnuzilla/)
Then, open **about:config** in firefox, we will need to change 2
keys. Firefox needs to know that we don't want to use our user's
locale as Firefox language and which language we want to set.
+ set `intl.locale.matchOS` to `false`
+ set `general.useragent.locale` to the language code you want (eo for esperanto)
+ restart firefox/icecat
you're done ! *Bonan tagon*