Add-ons hosted on Mozilla Add-ons should be of high quality and give users an improved web experience. We look for the following things when deciding whether an add-on is appropriate to be public and unrestricted:
Are you responsive? We expect that an author who is promoting their add-on to our applications' many users is responsive to problem reports, maintains their contact information, and updates their add-on promptly to keep current with Firefox releases and changes in our policies. This doesn't mean that you have to reply to every question that someone posts in the discussions, or that you even need to fix every bug, but we do expect that you will respond to issues in a manner that's appropriate to the severity of the issue in question.
Is the add-on clearly and accurately described? It's of the utmost importance to us that users get what they expect when they try a new add-on. Your add-on name should be clear and concise, and you should refrain from using special characters or numbers to get higher search rankings or for decorative purposes. Your description should provide details about what the add-on does, how a user should take advantage of it, and what the user should expect when they install it. Links to external documents for detailed instructions are fine, but the description itself should cover the basics and leave users confident that they know what they'll get. Also, it is important that you maintain version notes appropriately as you improve and change your add-on. Users should be able to see what's new in an add-on they may have tried previously, and should be made aware of changes that might affect their current use of the add-on when they update.
Are all privacy and security concerns clearly spelled out? This is an aspect of a clear and accurate description, but such an important one that we feel it deserves specific mention. Many very useful and well-written add-ons manipulate some form of user data, or can present security hazards if misused; they are welcome on the site, but they must make it very clear to users what risks they might encounter, and what they can do to protect themselves.
Has the add-on been well-tested, and is it free of obvious or serious defects? One important thing that we look for when considering an add-on is whether its user reviews indicate that it has received thorough testing, and that it doesn't have serious problems or negative impacts on the browser. If reviewers report problems such as major performance issues, crashes, frequent problems using the functions of the add-on, or spamming of messages to the error console, you should take those reports to heart, and re-submit your add-on after you've addressed them as best you can. We don't expect you to perfectly optimize or have zero bugs — Firefox itself undergoes constant improvement in these areas — but we do want you to take reasonable efforts to minimize downsides, and to clearly call out cases where users may be surprised by those that remain.
Do the add-on and add-on author both treat the user respectfully? Your software should not intrude on the user unnecessarily, try to trick the user, or conceal any of its activities from the user. Users (or even non-users) are sometimes rude in their comments, and while we will do our best to filter out inaccurate reviews as they're reported to us, we do expect that authors will avoid retaliating with rudeness of their own.
Is the add-on useful to an appropriately wide portion of Firefox's users? Your add-on doesn't need to be the next Greasemonkey or Firebug, but if it is only useful to people at your company or who are part of a small web community, we may feel that it's not yet appropriate to put it in front of all of our users.
We are constantly looking at ways to improve the organization of the site to better accommodate add-ons that are exemplary in other ways, but are aimed at only a small community of potential users. Correctly categorizing and maintaining the metadata of your add-on will help us figure out how we can surface more of those sorts of add-ons to people who are most likely to benefit from them.
If your add-on just provides bookmarks or other simple access points to your site, it's probably not appropriate for the gallery. Like the rest of the Mozilla project, we love web applications and new web services, but Firefox add-ons should provide an improved browsing experience for the user and not just be a way to promote a new site or service through a Mozilla Add-ons listing.
Is the add-on free of unlicensed trademarks and copyrights? Though you may mean no harm to the holder of a trademark, or the owner of a copyrighted work, we can't host add-ons that infringe on trademarks or copyrights. If you don't have permission to use a trademarked name or image, please do not submit your add-on to us. If your add-on includes code that is copyrighted by someone else, and is not licensed to you to use in your add-on, please do not submit your add-on to us.
In terms of reuse of source code from other add-ons, if the author has not clearly stated that you are permitted to use his or her code in your own work — such as by placing it under an open source license — then you should assume that you do not have the right to do so. You can contact the author to seek such permission, but we can't provide you with any special rights to it just because it's listed on the site, or because the author isn't responding to your request.
This applies to the Mozilla Foundation's trademarks as well, including "Mozilla", "Firefox", and "Thunderbird". The Mozilla policy on trademark use is designed to protect against confusion, and prevent the trademarks from being overturned due to lack of protection; please respect the need for such protection, and help us preserve some of the most valuable assets of the Mozilla Foundation.
Selecting an appropriate license for your add-on is a very important step in the submission process. A license specifies the rights you grant on your source code and is important in protecting your intellectual property.
During the add-on submission process, you will be presented with a list of popular licenses to choose from, as well as the ability to specify your own license. It is best to consult with a legal professional about which license option is best for you. Choosing the right license for your source code will help to prevent confusion and code conflicts in the future.
Last updated: January 13, 2011
Find out what is expected of add-ons we host and our policies on specific add-on practices.