Mozilla Add-ons is the official Mozilla Foundation

Mozilla Foundation

The Mozilla Foundation is a non-profit organization that exists to support and provide leadership for the open source Mozilla project. The organization sets the policies that govern development, operates key infrastructure and controls trademarks and other intellectual property...

 website

Website

A website, also written as Web site, web site, or simply site, is a collection of related web pages containing images, videos or other digital assets. A website is hosted on at least one web server, accessible via a network such as the Internet or a private local area network through an Internet...

 to act as a repository for add-ons for Mozilla

Mozilla

Mozilla is a term used in a number of ways in relation to the Mozilla.org project and the Mozilla Foundation, their defunct commercial predecessor Netscape Communications Corporation, and their related application software....

 software, including Mozilla Firefox

Mozilla Firefox

Mozilla Firefox is a free and open source web browser descended from the Mozilla Application Suite and managed by Mozilla Corporation. , Firefox is the second most widely used browser, with approximately 25% of worldwide usage share of web browsers...

, Mozilla Thunderbird

Mozilla Thunderbird

Mozilla Thunderbird is a free, open source, cross-platform e-mail and news client developed by the Mozilla Foundation. The project strategy is modeled after Mozilla Firefox, a project aimed at creating a web browser...

, SeaMonkey

SeaMonkey

SeaMonkey is a free and open source cross-platform Internet suite. It is the continuation of the former Mozilla Application Suite, based on the same source code...

, and Mozilla Sunbird

Mozilla Sunbird

Mozilla Sunbird is a free and open source, cross-platform calendar application that was developed by the Mozilla Foundation, Sun Microsystems and many volunteers...

. These add-ons include extensions, themes, dictionaries, search bar "search engines," and plugins. Because of its addons.mozilla.org domain name

Domain name

A domain name is an identification string that defines a realm of administrative autonomy, authority, or control in the Internet. Domain names are formed by the rules and procedures of the Domain Name System ....

, the site is informally also known as AMO.

In contrast to mozdev.org

Mozdev.org

mozdev.org is a website that offers free project hosting and software development tools to the Mozilla community. Many Firefox extensions are hosted on the site, but Thunderbird and SeaMonkey extensions and stand-alone Mozilla-based applications can also be found. It is free to set up a project...

 which provides free hosting for Mozilla-related projects, Mozilla Add-ons is targeted to end-user

End-user

Economics and commerce define an end user as the person who uses a product. The end user or consumer may differ from the person who purchases the product...

s, not just software developer

Software developer

A software developer is a person concerned with facets of the software development process. Their work includes researching, designing, developing, and testing software. A software developer may take part in design, computer programming, or software project management...

s. Many Mozilla applications contain direct links to the website, and contain settings to poll for updates to the extensions and the application itself. Firefox 3 includes features for retrieving and displaying content from the website in the add-on manager.

On January 30, 2008, it was announced that over 600 million add-ons had been downloaded from the site and that over 100 million add-ons automatically check the site for updates every day.

History

Formerly, Mozilla Add-ons was known as Mozilla Update (or UMO, as the hostname

Hostname

A hostname is a label that is assigned to a device connected to a computer network and that is used to identify the device in various forms of electronic communication such as the World Wide Web, e-mail or Usenet...

 was update.mozilla.org). The site underwent several changes its first launch and its becoming AMO.

• A major rewrite of the public pages was launched on April 4, 2006.
• A visual refresh of the Firefox pages was pushed on October 24, 2006 to correspond with the launch of Firefox 2 and the newly styled mozilla.com.
• A complete rewrite of both the developer and public pages, codenamed Remora
  Remora
  The remora , sometimes called a suckerfish or sharksucker, is an elongated, brown fish in the order Perciformes and family Echeneidae...
  
  , was launched on March 23, 2007.
• Another visual refresh, "Remora 3.2", launched spring 2008.