XPCOM
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XPCOM (Cross Platform Component Object Model) is a simple, cross platform component model similar to CORBA or Microsoft COM. It has multiple language bindings and IDL descriptions so programmers can plug their custom functionality into the framework and connect it with other components.
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The Model
It is one of the main things that makes the Mozilla application environment an actual framework. It is a development environment that provides the following features for the cross-platform software developer:
- Component management
- File abstraction
- Object message passing
- Memory management
This component object model makes virtually all of the functionality of Gecko available as a series of components, or reusable cross-platform libraries, that can be accessed from the web browser or scripted from any Mozilla application. Applications that want to access the various Mozilla XPCOM libraries (networking, security, DOM, etc.) use a special layer of XPCOM called XPConnect, which reflects the library interfaces into JavaScript (or other languages). XPConnect glues the front end to the C++-based components in XPCOM, and it can be extended to include scripting support for other languages: PyXPCOM already offers support for Python, PerlConnect provides support for Perl, and there are efforts underway to add .NET and Ruby language support for XPConnect.
On the developer side, XPCOM lets you to write components in C++, JavaScript, Python, or other languages for which special bindings have been created, and compile and run those components on dozens of different platforms, including these and others where Mozilla itself is supported.
The flexibility to reuse the XPCOM components from the Gecko library and develop new components that run on different platforms facilitates rapid application development and results in an application that is more productive and easier to maintain. The networking library, for example, is a set of XPCOM components that can be accessed and used by any Mozilla application. File I/O, security, password management, and profiles are also separate XPCOM components that programmers can use in their own application development.
Future development
An initiative known as XULRunner attempted to split XPCOM components from Mozilla itself. The objective is to turn Mozilla into a cross-platform development environment comparable to that of Java or .NET.
References
- Mozilla Foundation. (2005). Why to Use Mozilla as an Application Framework (http://www.mozilla.org/why/framework.html). Retrieved February 26, 2005.
See also
External links
- XPCOM Project Homepage (http://www.mozilla.org/projects/xpcom/)
- XPCOM Reference (http://www.xulplanet.com/references/xpcomref/)
- XPCOM Part 1: An introduction to XPCOM (http://www-128.ibm.com/developerworks/webservices/library/co-xpcom.html)