An add-on runs separately from the Foswiki scripts, e.g. for data import, export to static HTML, etc. Add-Ons normally do not call any Foswiki code directly, though may invoke Foswiki scripts. There are different types of add-ons, they may be stand alone scripts, browser plugins, office tool extensions, or even a set of topics that form a wiki application.
See other types of extensions:Contribs, Plugins, Skins
Use /bin/configure to browse or search the list of extensions available from Foswiki.org, and to install the extension.
Or, use the tools/extension_installer script to download and install the extension.
Or, download an extension package from some other source, and unzip it.
Follow any special installation instructions in the AddOn topic.
Creating new Add-Ons
New extensions in this category should be created as a Contrib. AddOns are deprecated. Visit Foswiki:Development/ExtensionDeveloperGuide for more details.