From MozillaZine Knowledge Base

about:plugins is a feature of Mozilla browsers that displays a list of installed and detected plugins, including the file name and associated MIME types. In addition to plugins found in the installation directory plugins folder, it also lists plugins installed in other locations that are detected via plugin scanning.

Note: In Firefox 3 and in SeaMonkey 2 (currently in Alpha at time of writing), disabling a plugin via "Tools -> Add-ons (or Add-on Manager) -> Plugins" will remove it from the about:plugins list and re-enabling a disabled plugin will add it back.

To display a list of detected plugins:

• Firefox: Type about:plugins in the Location Bar (address bar) and press the Enter key.
• SeaMonkey and Mozilla Suite: Open the Help menu and choose "About Plug-ins".

To show the full path to the plugin instead of just the file name, type about:config in the address bar and press the Enter key. Find the preference plugin.expose_full_path and change the value to true (double-clicking the preference name will toggle the setting).

This screenshot shows the first part of an about:plugins list in Firefox 2, on Windows.

See also

• Issues related to plugins