XPCOM

<p>Cross Platform Component Object Model (XPCOM) is a <a href="/facts/Cross-platform/16zqdvNR">cross-platform</a> <a href="/facts/Component-based_software_engineering/eW5wvSHC">component model</a> from <a href="/facts/Mozilla/FevL9Itn">Mozilla</a>. It is similar to <a href="/facts/Component_Object_Model/2DtIAufW">Component Object Model</a> (COM), <a href="/facts/Common_Object_Request_Broker_Architecture/VUDlTHs5">Common Object Request Broker Architecture</a> (CORBA) and <a href="/facts/System_Object_Model/qsIp6YLa">system object model</a> (SOM). It features multiple <a href="/facts/Language_binding/V5HW4Wr4">language bindings</a> and <a href="/facts/Interface_description_language/FpByLf4X">interface description language</a> (IDL) descriptions, which allow programmers to plug their custom functions into the framework and connect them with other components.
</p><p>The most notable use of XPCOM is within the <a href="/facts/Firefox/xez2zv8H">Firefox</a> web browser, where many internal components interact through XPCOM interfaces. Furthermore, Firefox used to allow <a href="/facts/Add-on_(Mozilla)/F0A6ctBz">add-ons</a> extensive XPCOM access, but this was removed in 2017 and replaced with the less-permissive <a href="/facts/Browser_extension/jzkeh57V">WebExtensions API</a>. Two <a href="/facts/Fork_(software_development)/D6khxhpr">forks</a> of Firefox still support XPCOM add-on capability: <a href="/facts/Pale_Moon_(web_browser)/8Wye08yN">Pale Moon</a> and <a href="/facts/Basilisk_(web_browser)/GqmdGwc9">Basilisk</a>.
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XPCOM open-in-new

XPCOM