The tabbed browsing system allows one 'main' Firefox window to contain 
several tabs, each of which contains a different open web page.  Using this 
method, you can quickly switch back and forth between multiple pages without 
needing to have several instances of Firefox open.  

To open a new tab, either right click on a link and select 'open in new tab' 
or choose 'file\new tab' from the menu bar.  Each tab has its own address 
bar and can be navigated independently.  You can automatically open a link 
in a new tab by 'middle-clicking' on it or dragging and dropping the link into 
the tab bar.
 One very neat feature that             
             
           is enabled with the use 
of tabbed browsing is the ability to assign multiple websites 
to a single 'home page.'  You can open up as many 
tabs as you'd like, set each of them to a different 
favorite  web page, then go  to 'tools\options\general' and click the 'set 
home pages' option. Now whenever you open Firefox or click the 'home' button, each  
site will open in a separate tab. I simply love this feature!  
Better yet, clicking the home page button while you have tabs open to other 
pages will not close these tabs. Instead, your home page tabs will be added on 
to the list. 
Overall, tabbed browsing certainly makes using Firefox faster and more enjoyable than using IE. Once you've gotten used to it, you definitely 
miss  the feature as you plod along in IE6 through all 
the pop-up infested websites.  We'd imagine the next version of Microsoft's browser 
will incorporate this feature.  
Popup Blocking and Alerts
The Firefox 1.0 browser implements pop-up blocking by default, in a similar manner to the WinXP 
Service Pack 2 upgraded version of Internet Explorer.  An alert bar appears 
at the top of the screen whenever a pop-up is intercepted.  Clicking the 
bar gives you the choice on allowing the pop-up for that particular site.  
 

The pop-up blocker seems to work very well in our experience, and is very 
non-intrusive. As we said, it's virtually identical to the method seen in the 
latest version of Internet Explorer. 
Website-initiated software downloads are generally 
handled with a prompt for permission from the user, though these downloads can be disabled completely through the 'tools\options' menu. 
If the page you are viewing requires a plugin like Macromedia 
Flash Player to open  some content, the alert bar will 
inform you of this. You can click the bar to download the required 
plugin, which is a nice touch.  Any sections of the web page that require 
a plugin you don't have are replaced  with a logo, and caption explaining their 
absence. Firefox also allows you to click on these sections to initiate the 
download as well.  

The Firefox browser's handling of pop-ups, alerts and plugins is 
excellent.  The necessary features are enabled by default, they work well 
and are effortless for novice users.