addons.mozilla.org and several other Mozilla services, including the Mozilla Labs Apps Developer Preview, are currently experiencing performance and availability issues. Mozilla IT is actively working to restore service, and you can view the current status here. Thanks for your patience.
About the Author
Justin is a Product Manager helping experimental projects reach their potential in Mozilla Labs. He previously worked on the Firefox Marketplace for HTML5 apps and led the Firefox Add-ons team, helping millions of users customize Firefox to make it their own.