Why Are Extensions Created?

The numerous third-party extensions available for Firefox are created for a variety of reasons. In many cases, extensions are created by members of the open source community who might have a passion for a particular element that they think will help all Firefox users. Other extensions, such as the Mozilla Amazon Browser, are created as a "proof of concept" to showcase the power of XUL and what you can do to develop web applications with Mozilla. Other extensions are created to satisfy the needs of a particular target audience. A good example of such an extension is Biobar, a search toolbar for searching bioinformatics databases that also provides links to bioinformatics tools. In other instances, the popularity of sites such as Google has spawned a number of extensions that help optimize the Google search experience.

FRIDGE

Google is popular, and extension developers have definitely taken notice, because many extensions have been developed for Firefox that are aimed at Google power users. For example, the Google Pagerank Status extension displays the Google page rank in the Firefox status bar. The GooglePreview extension provides a little more visual information because it inserts preview images of websites, Amazon products, and stock charts when you return a set of Google search results. The following are some other extensions you can check out to add some horsepower to your Google experience:

• Googlebar (discussed later in this chapter)

• Google Preview

• Google Pagerank Status

• SearchStatus

• FireluckyBox

• LookAhead

• McSearchPreview

• Define Word

FAQ: What is XUL?

XUL (pronounced "zool") is an abbreviation for Extensible User-Interface Language. In the world of software development, XUL is used to help define what the UI (User Interface) will look like. The XUL language defines things like where scrollbars and text boxes will appear, but it doesn't drill down to the level of what that scrollbar or text box will look like. The best-selling feature of XUL is the fact that developers can build applications that are cross-platform, and these applications can also be run without being connected to the Internet. Both the Mozilla Amazon Browser and the Mozilla Calendar, which are discussed later in this chapter, are excellent examples of the power of XUL at work. To learn more about XUL and to access some tutorials, head to http://www.xulplanet.com.