Firefox is still my favorite browser, however in the latest releases Mozilla does not include the Swedish language dictionary files anymore - for some reason. If you actually know the reason for this, please post it, since I am actually kinda curious to know :-)
This blog entry serves as a quick guide on how to install the Swedish dictionary in Firefox. It is based on these installation notes from Mozilla and that we have to fetch and extract the dictionary files from OpenOffice.
Since I am using Windows my dictionary folder is a:
C:\Program Files (x86)\Mozilla Firefox\dictionaries\
If you are using any other system you might have another path.
Download these files to the dictionary folder:
These files are taken from the OpenOffice Swedish dictionary version 2.12.
Just restart the browser.
Enable the new Swedish spelling by right clicking on any text area, pick Languages and then Swedish (Sweden). Done!