Mozilla Firefox
"Take back the web". What can I say, it's the best browser out there. IE isn't even a contender, even ignoring the fact that it's tied to a sub-standard operating system. Opera is nice - it runs beautifully on my Nokia 770 Internet Tablet and other low-end systems, but lacks the customizability of Mozilla Firefox. And plus, Mozilla was a true open source pioneer.
If you're here, you probably already know how great Firefox is - standards-complaint, F/OSS, lots of extensions (and you can write your own), secure, AND the session restore feature.
Issues
The only real issues that I've had with Firefox (aside from the memory leaks associated with running 38 extensions) stem from the fact that my laptop is an AMD64, running a full 64-bit version of openSuSE. It took a bit of tweaking, but I finally got Flash to work (who knows how I did it).
Customization
Having done as much web development as I have, along with many other things, I've customized my Firefox installation quite a bit. Admittedly, I've had some issues keeping those customizations across different machines, though mainly I just use my laptop.
Extensions
Application: Firefox 2.0.0.4 (2006102300)
Operating System: Linux (x86-gcc3)
- All-in-One Sidebar 0.7.1
Sidebar control with award-winning user experience! - Bookmark Duplicate Detector 0.6.3
Helps you find, move and remove duplicate bookmarks. It also notices you when you are adding a bookmark already in your Bookmarks. - CoLT 2.3.0
Adds a Copy Link Text item to the browser's context menu. - Compact Library Extension Organizer (CLEO) 3.0
Create multi-addon install package (Cleopack) - Copy as HTML Link 1.1
Creates an HTML link to the current page using the selected text and copies it - del.icio.us Bookmarks 1.5.43
Access your bookmarks wherever you go and keep them organized no matter how many you have. - DOM Inspector 1.8.1.4
Inspects the structure and properties of a window and its contents. - Domain Details 1.2
Get server, whois and domain information on the site you're visiting. - Download Embedded 0.5
Downloads all embedded objects on a webpage. - Dummy Lipsum 1.2.0
Generate "Lorem Ipsum" dummy text. - Email This! Bookmarklet Extension 2.0.2
Email This! will send a recipient the link, title, and text of the webpage you are viewing. - Extension List Dumper 1.8.0
Dumps a list of the installed extensions. - FEBE 5.0
FEBE - Backup your Firefox data - Firebug 1.05
Web Development Evolved - FireFTP 0.97.1
FTP Client for Mozilla Firefox. - FlashGot 0.6.8
Enables single and massive ("all" and "selection") downloads using the most popular external download managers for Windows, Mac OS X, Linux and FreeBSD (dozens currently supported, see Extension's Home Page for details). FlashGot offers also a Build Gallery functionality which helps to synthetize full media galleries in one page from serial contents originally scattered on several pages, for easy and fast "download all". - Google Notebook 1.0.0.18
Allows notetaking while browsing - Html Validator 0.8.4.0
Adds HTML validation to the View Page Source of the browser. The validation is done by Tidy from W3c. - JSView 1.2.9
View the source code of external stylesheets and javascripts. - LinkChecker 0.6.1
Check the validity of links on any webpage. - MeasureIt 0.3.6
Draw out a ruler to get the pixel width and height of any elements on a webpage. - Nagios Checker 0.10.4
The statusbar indicator of the events from the multiple network monitoring systems Nagios. Information is parsed from Nagios web interface. - Ook? Video Ook! 0.6.6
Ook? Video Ook! is able to download embedded videos from several web sites. - Open Link Host 1.3.2
Open the host of a link. - Paste Email 2.1.2
Paste emails and more into text fields. - QuickRestart 1.1.0
Adds a "Restart Firefox" item to the Tools menu. - Sage 1.3.10
A lightweight RSS and Atom feed aggregator. - Server Spy 0.1.2
Indicates what brand of HTTP server runs on the visited site. - ShowIP 0.8.05
Show the IP address of the current page in the status bar. It also allows querying custom services by IP (right mouse button) and Hostname (left mouse button), like whois, netcraft. Additionally you can copy the IP address to the clipboard. This extension was formerly known as ipv6ident. - TimeStamp Converter 1.3.5
Converts dates and timestamps. - TimestampDecode 0.1.4
Treats the selected number as an unix timestamp and displays a decoded date/time - Total Validator 4.2
Validates web pages in numerous ways - United States English Dictionary 2.0.0.6
English United States (en-US) spellchecking dictionary - UrlParams 2.01.02
Displays the websides get/post parameters in the sidebar. - View Dependencies 0.3.2.2
Adds a tab listing dependencies and their sizes in the Page Info window. - X-Ray 0.8.1
See the tags on a page without viewing the sourcecode. - Yellowpipe Lynx Viewer Tool 1.2.1
Displays a Lynx view of a web page via right-click, toolbar button or Tools menu.