Deprecated: This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.
Returns a sidebar object which contains several methods for registering add-ons with the browser.
The sidebar object returned has the following methods:
|Method||Description (SeaMonkey)||Description (Firefox)|
||Adds a sidebar panel.||
Obsolete since Firefox 23 (only present in SeaMonkey).
End users can use the "load this bookmark in the sidebar" option instead. Also see Creating a Firefox sidebar.
||Adds a sidebar panel, which is able to work in the background.|
||Dummy function; does nothing. See Autodiscovery of search plugins.|
Installs a search engine (Sherlock). Adding Sherlock search engines contains more details.
Note: This was made obsolete in Firefox 44, and has been removed completely in Firefox 59.
||Indicates if a specific search provider (OpenSearch) is installed.|
Mozilla-specific. Not part of any standard.
Removed in Firefox 102.
For more information see Firefox compatibility information in