XULRunner

infobox software
developer = Mozilla Foundation and community
latest release version = 1.9
latest release date = release date|2008|06|19
programming language = C++
operating system = Cross-platform
programming language = C++, XUL, XBL, JavaScript
genre = Runtime environment
license = Mozilla tri-license
website = http://developer.mozilla.org/en/docs/XULRunner

XULRunner is a runtime environment developed by the Mozilla Foundation for providing a common back-end for XUL applications. It replaced the "Gecko Runtime Environment", a stalled project with a similar purpose. [ [http://developer.mozilla.org/en/docs/GRE GRE - Mozilla Developer Center] ]

XULRunner is currently in the early stages of development. The first stable developer preview of XULRunner was released in February 2006, based on the Mozilla 1.8 code base, and alpha versions based on Mozilla 1.9 were released in 2007.

Uses

All XUL-based applications like Mozilla Firefox, Mozilla Thunderbird, Songbird, Flickr Uploader, SeaMonkey, Conkeror, Sunbird, Miro, Joost, Instantbird and TomTom Home 2.0 will be able to run on XULRunner.

The new installment of the computer game series Simon the Sorcerer, "", uses XULrunner.

The eMusic web site has a download application called eMusic Remote that uses XULRunner.

Adwords editor uses XULRunner. [http://code.google.com/p/xulrunner-adwords-editor/]

Benefits and rationale

Benefits of having a separate shared run-time environment are the same as those with shared libraries. Benefits to developers and source-based systems – that is, systems on which programs are compiled from source as opposed to downloaded in binary form – are decreased compilation time, less bandwidth needs and less storage space needed. Benefits for use on binary-based systems are similarly less bandwidth and storage use.

Less storage space and, in the case of running multiple XUL-based applications at once, less memory use only apply when the system uses more than one application that depends on the run-time environment. If either the run-time environment or the application are updated separately at different times, which is more likely in the case that it is widely used for software other than that written by Mozilla, then this would be more commonplace. In the case of source-based systems, developers using common code would not have to include said code in distributed packages.

Additionally in the case of XULRunner, being a markup and interpreted or possibly in the future "just-in-time" pre-compiled script run-time environment, developers may not need to compile any source code into object code (binary) at all for their applications that solely use markup and script languages.

Possible problems with using a common run-time environment include applications that are written using features of one version of the run-time environment that are not included (perhaps due to obsolescence), and replaced with different functionality, which would result in "dependency hell" – a technical jargon term for dependencies on specific versions. This may be avoided by making systems able to install multiple versions of XULRunner and allowing developers to use a specific version at run-time, or by providing compatibility layers. This is not a problem with dependent software that is continually updated and rewritten.

See also

* Mozilla Prism

* Gecko (layout engine)

References

External links

* [http://wiki.mozilla.org/XUL:Xul_Runner XULRunner wiki site]
* [http://developer.mozilla.org/en/docs/XULRunner XULRunner Documentation]
* [http://developer.mozilla.org/en/XULRunner_Hall_of_Fame XULRunner Hall of Fame]
* [http://benjamin.smedbergs.us/blog/2007-05-15/xulrunner-what-we-are-doing/ XULRunner: What we are doing] (Mozilla plans for the 1.9 timeframe)
* [http://ftp.mozilla.org/pub/mozilla.org/xulrunner/ XULRunner source code]
* [http://video.kiberpipa.org/media/SU_Harnessing_the_Mozilla_platform/play.html Brian King 2005 Media]
* [http://brian.mozdev.org/presentations/cyberpipe2005/slides.html Brian King 2005 Presentations Slides]