Although most components available from XPCOM are written in C++, the XPConnect/XPCOM pairing can also accommodate other languages. 2002, David Boswell, Creating Applications with Mozilla, →ISBN, page 241:
XPCOM is entirely internal to the Mozilla Platform. XPConnect is the glue that turns XPCOM-compliant objects and their interfaces into JavaScript host objects. 2004, Nigel McFarlane, Rapid Application Development with Mozilla, →ISBN, page 176:
XPCOM enables component software development, a paradigm that is heavily leveraged in the Mozilla product line. DLLs that implement the required external functions and classes defined for this purpose by XPCOM can be registered as components with a Mozilla-based project, and applications can then uses XPCOM to query these components for classes and interfaces, and then make calls against the interfaces to obtain the services provided by the component. 2007, Syd Logan, Cross-Platform Development in C++, →ISBN:
These XPCOM interfaces are the starting point for all XUL elements. 2007, Kenneth C. Feldt, Programming Firefox: Building Rich Internet Applications with XUL, →ISBN: