Add-ons are like apps that you install to add features to Waterfox. They let you compare prices, check the weather, listen to music, send a tweet and more.
Get add-ons from the following places:
Archived Add-ons for Firefox : This is an archive of the Firefox add-on page when it had all add-ons available for every version. The search functionality does not work, so this is more useful if you know the direct URL of the add-on you want to use.
LegacyCollector : Mozilla has removed all "legacy extensions" from their add-ons site in November 2018, leaving many users of older "long term support" versions of the browser, as well as browser forks, dead in the water. This holds a (hopefully complete) collection of the removed extensions as they were available from addons.mozilla.org prior to this purge by the company.
Thunderbird Firefox Add-on Archive : This archive contains various (but not all) older style add-ons compatible with Waterfox. Search functionality works.
Classic Add-on Archive Extension : This is an add-on that installs into Waterfox and provides a local database of all available add-ons compatible with Waterfox. This catalog contains 93,598 versions of 19,450 Firefox add-ons created by 14,274 developers over the past 15 years using XUL/XPCOM technology.
Add-ons for Firefox : The current WebExtension catalog for modern Firefox. Waterfox will work with most extensions that show the "Add to Firefox" button.