Locating Extensions on the Web

Your recommended first stop for extensions is the official Mozilla repository, addons.update.mozilla.org (UMO), which can be accessed directly from the Get more Extensions link on the right side of the Firefox Extension Manager. UMO contains a categorized list of extensions that are updated frequently and can be sorted by platform and version number. UMO also breaks down extensions into several categories, including top-rated, most popular, and newest.

In addition to UMO, there are a number of other places on the web that you can find extensions for Firefox.