[I use a Mac, so all the images in this post are of the Mac user interface. The UI for other platforms will differ slightly. Click on pictures to view other sizes.]
Plugins are small third-party programs that can be added to Firefox to manage content that Firefox does not handle itself. Popular plugins include Adobe’s Flash player, Quicktime, Windows Media Player, Java, RealPlayer, and Shockwave. Without the Flash plugin, for example, you wouldn’t be able to watch YouTube videos.
In Firefox 2 the only way to get information about what plugins you have installed is to type “about:plugins” in the location bar. This brings up a page of somewhat complicated, detailed information about the plugins that looks like the following screenshot. The page is a simple list of information — there is no way to interact with the plugins through the page at all.
Firefox 3 still has the about:plugins page, but also offers a much more useful new feature as part of the revamped Add-ons Manager. In Firefox 3, you can open the Plugins section of the Add-ons Manager by going to the “Tools” menu, selecting “Add-ons”, then clicking on the “Plugins” tab of the Add-on Manager.
Here you can see a much simpler and easier to understand list of installed plugins and their version numbers. Each plugin can also be enabled or disabled with a single click, and you can go to the original source of the plugin (if it is specified) by right-clicking and selecting “Visit Home Page”.
In addition, like with other add-ons in Firefox 3, if a plugin is found to contain a security vulnerability, Firefox will automatically disable it and tell you where to get an updated version. This is a significant security improvement for Firefox, which previously had no way to let you know that you had bad plugins installed. The list of blocked plugins is stored locally on your computer, and Firefox periodically verifies that the list is completely up to date. If Mozilla knows about a vulnerable plugin, you’ll be informed and protected automatically within 24 hours.
And there you have it. Another small but vital improvement that makes Firefox 3 significantly safer and easier to use.