It's been a couple of days since I've made a post singing the praises of Mozilla or Firebird, so I figured I'd start the week right. ;-) Although the default features of Mozilla and Firebird are extensive, one of many nice things about them is the ability to incorporate extensions (formerly known as plugins in Netscape) and add-on projects that contribute even more useful features and capabilities. For a fairly comprehensive list of extensions you can consult this site, and for an overview of active projects take a look here. Here are some of my favorites:

• Searchthis - allows you to highlight a term and conduct a search by right-clicking. I use this all the time for dictionary searches.
  
• Adblock - complements the already extensive ad-blocking capabilities by allowing you to precisely block server paths for ad graphics.
  
• Flash Click To View - disables all Flash animation, blocking annoying Flash ads, but also getting rid of Flash animation you might want to see (like HomeStar Runner!). You can easily click on the Flash box to watch the animation if you so desire, though.
  
• Auto Scroll - lets you use the AutoScroll feature available on the middle button of come mouses; might be incorporated into upcoming versions of Mozilla.
  
• Download Statusbar - allows you to remove the download status window that pops up, replacing it with a dynamic graphic that appears in a status bar at the bottom of the browser window.
  
• Mycroft - choose among hundreds of different search engine sites to add to the default search options.
  
• Leech - download all the files of a particular file extension linked to on a page by right-clicking, like graphics, animations, zip files, etc.
  
• Language Menu - adds a sub-menu under "Tools" which allows the server to provide a localized version of a page. Great if you look at a lot of foreign language pages.
  
• Prefbar - a very useful toolbar that adds "utility buttons, user agent spoofing, web links, and more." The user agent spoof sometimes fools sites that "require" M$ IE.
  
• Preferential Toolbar - quite the power extension; adds an "advanced preferences" option under the "tools" menu that lists any and every modifiable parameter, allowing you to easily customize almost any preference.
  
• Blog This - allows you to post the current page to your Blog by right-clicking on the it. This type of feature is also available as JavaScript bookmarklet that you drag to your links toolbar.
  
• Themes - a site that lists all available themes for Mozilla, Firebird, Netscape 7.x, etc. I personally haven't changed my default Firebird theme, but it's nice to know that you can.
  
• Plugindoc - not really a plug-in, more of a resource to help install some pesky application plug-ins, like Java, Shockwave, and ActiveX.

It could be argued that some of these features should be incorporated into Mozilla and Firebird as default features, but I think that not everyone wants or needs all of these things. Some of them I can't live without, but others would probably unnecessarily complicate things for users. When it comes down to it, I prefer being able to customize browsers the way I want rather than have bugs features forced upon me...

P.S. Make sure you restart the browser after installing each extension. Sometimes I encountered some problems trying to do a whole bunch at once without closing and restarting...