Disabling the GFX rendering solves some problems of displaying text as bars instead of letters at Linux systems.

This checkbox allows to toggle zoom modes. Default in latest browsers is to zoom text and pictures. Uncheck this checkbox to just zoom text and keep pictures in their original size.

This checkbox enables or disables a site specific context menu.

This checkbox toggles the automatical refresh or forwarding for pages.

This menulist allows to have more control on how cookies are handled. It allows to switch between the following values: No cookies, All cookies, Cookies from originating domain, and Cookies from originating domain + existing 3rd-party cookies.

This checkbox makes it easy to enable or disable the javascript-based PDF reader, which is included with current Firefox releases.

If you want to decide, if a eBay member is trustworthy, then the best way to do this is to have a look at the neutral and negative feedbacks. This button grabs the eBay nickname from your currently viewed member page or article page and forwards it automatically to the "negative/neutral feedback search engine" of http://www.toolhaus.org/.

This button will create a clone of the currently viewed tab, including its back/forward history.

This button clears all finished downloads in your download manager. Note that version 2.0 just uses the PrefBar builtin function "prefbarClearDownloads", which is part of the builtin "Clear All" button.

This is the same as "File -> Work Offline" and the same as the "plug icon" on the lower right in the SeaMonkey window. As SeaMonkey has this one built in, it's mostly for Firefox, which doesn't have it. But if a SeaMonkey user wants to use this one: It will work there, too.

This menulist allows to switch the browser GUI language easily and so is especially interesting for everyone, who develops an addon, which is translated to more than one language. It also allows to switch to locales, you don't have a language pack installed into your browser!

To activate the new locale, you have three options:

• The next window, you open after changing the locale, uses the locale, you selected.
• You may use the "Reload Browser" button of the Addon Developer Buttons button set, to reload the current browser window with the new locale setting applied.
• The Restart browser button can be used to quickly restart the full browser with the locale, you selected in the menulist

This button set contains 8 buttons, useful for Addon developers

• Chrome Errors checkbox: Allows to enable the display of chrome javascript errors in error console (and also enables the error console on newer Firefox releases, if checked).
• Extension Install Log checkbox: Toggles verbose logging of extension install/update problems to the Error Console (see "Chrome Errors checkbox").
• Scratchpad for Browser checkbox: This enables to run JavaScript code snippets in the chrome context of the Scratchpad from the Tools menu
• About Config Warn checkbox: Toggles the "warning message" displayed if you open "about:config".
• XUL Cache checkbox: Toggles the XUL cache
• JavaScript Strict checkbox: Toggles javascript strict mode
• Enable dump() checkbox: Allows to enable debug error messages, displayed via the "dump()" command
• Reload Window button: Reloads current browser window, and all overlays, without needing to restart browser!

This checkbox toggles if new tabs should be loaded in foreground or background. If the checkbox is checked, new tabs are focused automatically.

This button clears all cookies belonging to the domain of the currently active browser tab.

This button allows the user to expire and delete entries from the browser history older than a specified number of days. The number of days is input in a popup dialogue, which already contains the default of 30 days. This is a work-around for bug 660646.

This Menulist contains entries to open the permissions dialog for the following items: Popups, Images, Installation and Cookies
This one primarily targets SeaMonkey, which no longer has a built-in way to call those dialogs (since SeaMonkey only has the "Permissions manager" to manage those permissions). As I think the old way, to manage permissions, still has some advantages over the "Permissions manager", I thought it is a good way to restore it. Nontheless, this button should also work for Firefox users who want "quick access" to those page permissions dialogs.

Have you ever be interested in what software is running on the server, hosting the page, you are currently viewing? Then you need this button! On most servers it at least is able to fetch the name of the server software (Apache, ...) and the name of the operating system (Unix, Linux, ...). Many servers will even tell you which PHP version, MySQL version, ... they are running.
PrefBar 6.0.1 required to import this button!

This checkbox allows to switch on/off the Foxit Reader and Adobe Acrobat Reader PDF plugins.

This checkbox allows to switch on/off the Microsoft Silverlight plugin.

This checkbox replaces the mozilla-builtin support of a userContent.css file. The CSS file has to be named "userstyle.css" and has to be placed in the same directory, you would place a userContent.css file to. If you already have a userContent.css file, you may just rename it.
This checkbox resolves two big issuses of the official user stylesheet support. At first you may enable/disable your CSS file without restarting your browser and at second, as checking the checkbox causes a reread of the CSS file, even modifications can be applied directly, without having to restart the browser, by just unchecking and rechecking the box.
As an additional feature, you may open the file into your preferred editor by shift+clicking on the box. If doing this for the first time, you'll get instructions on how to enable this.

This button closes all but the current tab.

This checkbox toggles between a set "minimal font size" (do this in your browser configuration) and "normal font size".

Does what it says: Opens addon manager.

Reloads the current tab and all other tabs in the current window, which show a page from the same domain as the current tab.

Triggers a browser restart including session restore.

This is a Menu, which contains the items "Print", "Preview" and "Setup"
As PrefBar may also be displayed on popup windows, this makes it possible to print those windows easily.
You may also use this as a template for your buttons, as it shows, how to abuse an extlist, to place several commands into it.

Launches Bookmark Manager.

This checkbox allows to enable/disable the geolocation feature, part of current browsers. As this is always "opt-in" in both (SeaMonkey/Firefox), this is not as critical as it sounds like, but maybe someone wants to be able to kill down the feature completely.

This button prints out a list of all installed extensions, ready for you to copy and paste into forums or whereever you need this information.

This menulist allows to spoof the Referer, sent to pages, you visit, to any value, you want. Just create a list of the values, you need, and select as required.

This one will save the whole page, you are currently viewing, to one big image file. You have the choice to either save in PNG or JPEG format.

Everyone knows the problem. You surf the web, click on a link and it opens in a new window (or tab) and not in the window, where you currently are. Unchecking this button disables most of the ways, webmasters may use to open new windows, and so it's finally your choice, where you want to open links.

I recommend you to disable this one after you've unchecked it, to not waste space. You most probably will never want to re-check it and will only need it again, if some other extension, or the browser itself, changes settings.

This button file contains one button to validate HTML and one to validate CSS using the services of w3c.org. The tabs are loaded in background and PrefBar tries to set the background color of the tab to red for failed and green for passed, so you don't have to switch to the tab to see the result.

This button will transfer any popup window, that gets opened, back to a "real browser window", by re-enabling menu bar, any toolbar, the sidebar and the status bar. You have to enable PrefBar for popup windows, to be able to use this one.

This one will toggle "Meta Redirects" for the current tab.

This button may be useful for web developers or for people, who want to log out everywhere without closing the browser. It kills the current browser session, whithout killing the browser. To do this, it kills all session cookies and all HTTP authentifications.

This button immediately reloads the proxy information, if you have configured your browser for "automatic proxy configuration"

This file contains two buttons to modify the URL of the currently displayed page.
The ".." button drops one directory level. So "http://www.example.com/path1/file1.html" gets "http://www.example.com/path1/"
The "/" button drops all directory levels. So "http://www.example.com/path1/file1.html" gets "http://www.example.com/".

This checkbox makes it possible to toggle CSS styling for the current tab

Restores the default font size. This is useful when you cannot remember how many times you clicked Font+ or Font-.

Allows switching between the three different settings for handling images:
(1) load all,
(2) do not load any, or
(3) load only from the page's domain.

Launches Profile Manager (useful for switching profiles).
SeaMonkey only!

Enables (checked) or disables (unchecked) the tooltip-like preview of tab pages.
SeaMonkey only!