You use Firefox and/or Thunderbird, and you get a list of dictionaries with plenty of useless entries: here's how to remove them.
For once, an article on Windows.
You are using a webmail (Gmail, Yahoo ...) and also applications or documents including mailto links, so, you would like the links to open Firefox or Chrome on your webmail: follow the guide !
To develop web site, you might want to add plugins to Firefox browser.
You want to run a Java application in your web browser Firefox (typically a webinar), you need a Java plugin installed ! Here's how to do it, in Ubuntu 12.04.
Web browsers Internet Explorer and Firefox do not manage the box model the same way.
How to install the wiktionary in Firefox search bar.