The recently released Netscape 7 may be the most well known browser built with Mozilla, but it certainly is not the only one. Mozilla is being used as a framework to create many different types of applications including OEone's HomeBase DESKTOP, ActiveState's Komodo IDE, and all of the projects hosted on mozdev.org. People are also using Mozilla to create their own custom browsers [link to brian's article].
One of the benefits of Open Source development is that it prevents someone from having to reinvent the wheel whenever they are working on developing something that has been done before. Since the Mozilla community is already working on a browser, wouldn't it be better if everyone just focused on making that browser as good as it can be?
Instead of being a bad thing, the several different browser development projects that are currently underway are one of the Mozilla community's greatest assets for the simple reason that one browser can not be all things to all people. Each new browser that gets built is filling a need that is not being met by any other existing option. Each new browser that is built also has the potential to appeal to a whole new audience that will help expand Mozilla's adoption.
Another positive benefit of having multiple browsers is that it helps avoid compromises that don't make anyone happy. AOL is interesting in Mozilla because they want a browser that appeals to novice Internet users. The Mozilla developers who contribute their time to the project want to create a powerful browser with a collection of advanced features. If the community is locked into working on only one browser, then the end result of this development process will be a browser that has a bewildering array of features and that doesn't appeal to either intended audience.
If one browser can't possibly to beginning users and power users at the same time, why not create two different browsers? For that matter, why not create as many different browsers as there are different types of users? Since all of these browsers are built using Mozilla, web developers can create sites that work with Mozilla and users can browse with whatever tool suits them best. Everyone wins.
There are two main types of browsers that are built using Mozilla. Some developers choose to create their application using XUL, Mozilla's XML-based User Interface language. Other developers prefer to use just Gecko, Mozilla's rendering, and then create the GUI of their browser using one of the toolkits native to a specific platform. There are Gecko based browsers for each of the major operating systems in use today, including Windows, Linux and Mac OS X.
The goal of the Chimera project is to create a best-of-breed browser for the Mac OS X platform with an user-interface that is as simple and as clean as possible. Chimera uses Cocoazilla, a variant of Fizzilla that consists of a UNIX back end connected to a Cocoa front end. Since Chimera uses a native toolkit to create it's GUI it can't run on any platform other than OS X, but since it doesn't use XUL it is faster than the default Mozilla browser on the same computer (applications written with XUL will always be slightly slower than applications written with native toolkits because *** need explanation here, ask brian ***). The most recent stable release, version 0.4, is available for download along with nightly development builds.
Chimera's tabbed browsing mode
Galeon and K-Meleon are projects that also have the goal of creating a simple standards-compliant browser using Mozilla's rendering engine. Galeon uses Gecko to create a browser for the GNOME desktop and K-Meleon uses Gecko to create a Windows only browser. The latest stable version of Galeon can be downloaded for a variety of Linux distributions. There are also alpha versions available for Galeon2, which is a new major version of the browser that takes advantage of the huge changes in architecture in the new GNOME 2 desktop. The latest version of K-Meleon can be downloaded for Windows and it includes a number of stability and configuration changes over earlier versions. Other Gecko based browsers include SkipStone and Q.Bati.
One of the first alternate browsers, Aphrodite was created as an alternative to the default interface that ships with Mozilla. Aphrodite includes a number of it's own themes, including FruityGum, Inferno and two flavors of the Sullivan skin. The crash recovery system Total Recall is also integrated into the browser. Development work continues on Aphrodite, although currently there isn't a new release that works with the latest version of Mozilla.
Aphrodite with the Sullivan grape theme
Beonex Communicator is another XUL based browser that is a user-focused browsing suite that also comes bundled with a mail client and a web page editor. The latest stable version, Communicator 0.8, is available for download for Windows and Linux. Some other projects include BrowserG!, Project Piglet, MercurySpider, and Dino.
The browsers that are currently under development using Mozilla are just the tip of the iceberg. One of the most interesting possibilities for future browser development comes from AOL, the same company that owns Netscape and that is the main sponsor of the Mozilla community. Currently the Windows version of the AOL client uses Internet Explorer as the core of it's browser, but their are indications that this way soon change. If AOL were to use Mozilla in a new version of their software, tens of millions of people would be exposed to Mozilla.
AOL has already made some moves in this direction. The latest version of the AOL client for Mac OS X uses Gecko as it's rendering engine. Gecko has also replaced Internet Explorer in CompuServe 7.0, the latest version of AOL's other online service. The decision to use Gecko in these two offerings are seen by many as ways for AOL to iron out any rough spots before they move forward with releasing the latest version of their AOL client for Windows.
Another interesting project to keep on eye on is Phoenix. There isn't much known about this yet, but there are some pages in bugzilla and on the mozilla.org site that have some information. It looks Phoenix is based off of an earlier project called m/b (short for mozilla/browser) and has a goal to create a user-friendly stand-alone browser that is free from most of the constraits placed on the default Mozilla browser. Builds of Phoenix aren't available right now, but it is possible to grab the source from CVS and build it yourself right now. There are instructions about how to do this in the project's README file.
Phoenix with the Customize Toolbar dialog
If there is a browser that you would like to use that isn't already under development, remember that you can always create your own browser with Mozilla [link to brian's article]. Each of the projects listed here could also use help with testing and development, so you can also contribute by adding features or fixing bugs to make these browsers even better. This wealth of browser options is a great strength, so let's hope that each of these projects continue to mature and innovate. Let 100 browsers bloom so that we can all have the perfect browser.