Firefox LogoHappily, one of the best things about the Mozilla Foundation’s flagship browser Firefox, is the sheer breadth of additional functionality provided by an active development community in the form of addons or plugins. There’s a great range in terms of ease-of-use, function and stability, some which are so useful as to almost warrant standard inclusion, others merely worth playing with from time to time. It should be noted of course that adding plugins can cause problems with Firefox’s stability and security, though many of those listed are fairly mature projects and should not pose much of a risk. Here are a few I’ve dabbled with from time to time:

Adblock or Adblock Plus – There’s fair advertising, and then there’s frankly unreasonable advertising. I can see the merits of allowing sites to earn funding through the placement of adverts related to their products, whether they come from Google or elsewhere, but some web adverts go too far. The popup plague of yesteryear might have been largely beaten back, but that doesn’t prevent wiley coders from placing wholly obtrusive flash adverts in every nook they can find. Unfortunately their actions can only serve to give web advertising a bad reputation, and drive people to finding ways of blocking adverts wholesale, obtrusive or otherwise. Of course there will always be a small minority of web users who cannot stand to see web adverts in any form, but for their purposes, and the folks seeking refuge from the advertising bombardment, Adblock/Adblock Plus will fulfil their every need.

To tell the truth, the history of these two projects confuses me, save to say that at one time or another one or both of these plugins has been under development. As I understand the current situation, Adblock Plus is the more highly recommended, as it’s more heavily featured, comes with some default filters to subscribe to which can get rid of most adverts with the minimum of fuss for the end user, and has a much reduced resource footprint to boot (pardon the pun).

BugMeNot – It’s a bit of a misnomer to include this in the list, since as a plugin it merely allows Firefox to hook directly into a particular website. Nevertheless, the idea behind the project is sound – to get round all those niggling little registration requirements which many sites use to restrict access to content. You know the sort—’Register here – it’s free!’ Which begs the question, if it’s free, why do I need to register? offers end users a way to take a stand against this requirement, allowing them to log in to sites using generic, registered accounts. It does not include paid sites, since the purpose is to simply avoid the need to register for further content. imdb offers a perfect example of this kind of behaviour—if you want to read comments about entries on their system, you need to register. As explains, you might consider this compulsory registration a breach of privacy, if you even fill it in truthfully! This little plugin integrates’s functionality into Firefox’s right-click context menu.

Clipmarks – Another website-based plugin, though this time the functionality is all that more apparent. Click a button and the Clipmarks plugin will allow you to highlight sections of a webpage that are of interest, be they sections of text, links, pictures or video. These clippings are then saved to Clipmarks‘ website, which requires registration and attempts to act like another social hub along the lines of StumbleUpon (featured later), although clippings can be saved both publicly and privately, and doesn’t require much information from the user. With all of these clippings fully searchable, the website offers to act as an online scrapbook, doing away with wholesale bookmarking to really collect only the most necessary scraps of information. The service also offers a way of sending clippings directly to a blog post, something I haven’t experimented with yet, although it might be worth exploring.

CustomizeGoogle – If you use Google as your primary search engine, but sometimes find yourself wanting a second opinion, CustomizeGoogle might be the answer. The plugin will offer links to other major search engines directly within the Google search, allowing you to quickly check the other options. But that’s only the beginning! You can also remove adverts, filter out websites of your choice from search results, increase privacy by randomising your Google userid, have suggestions offered whilst typing out a search string, amongst others, and all options can be chosen from a simple menu. Extremely useful and well-featured plugin—I won’t use Google without it!

Dog Ears – A bit of a throwaway plugin, though could come in quite handy. Basically, Dog Ears allows you to leave little markers on web pages, particularly useful to mark your reading place on a long webpage, though it is open to other applications. Works best with Firefox 2.0 and above, as dog ears are saved by default even when you close or navigate away from that page.

DownloadThemAll! – Probably the weakest link in Firefox’s armour at the moment is its default handling of downloads, which makes DownloadThemAll! a superb plugin to install for starters. Pausing and resuming are simply handled, as are multipart downloads to increase speeds (though this has always caused problems with certain websites). Probably its greatest strength is the ability to use it to glean links from a page, and filter out the ones to be downloaded to a location on your machine. All of this is of course fully customisable.

Firebug – One for the developers, Firebug allows the end-user to view, edit and debug the CSS, JavaScript or HTML of the sites visited, allowing for on-the-fly updates and alterations, a handy way to test changes and isolate a variety of problems. An extremely handy yet unobtrusive tool for webmasters and designers alike.

FireFTP – I’ll be honest, I haven’t actually used Internet Explorer 7 in order to tell how good its FTP functionality really is, but my experiences with previous incarnations of the browser put me off altogether! Its abysmal handling of this simple protocol put me off ever using a web browser to handle FTP again, instead opting for a standalone client (the current favourite in this regard being FileZilla). Whilst I still rely on this program for most FTP stuff as the protocol seems to be quite susceptible to security risks, FireFTP offers a decent, secure (so far), and most importantly convenient client for those minor FTP needs, particularly for browsing repositories anonymously.

FlashGot – If you want something like DownloadThemAll! (DTA) mentioned above, but already have a favourite download manager, FlashGot is probably the thing for you. With similar functionality to DTA, FlashGot allows for one, multiple or all links on a page to be downloaded quickly, fully integrated with a range of popular download managers. It also features an interesting gallery builder, synthesising media from scattered pages for easy downloading, though this is not something I’ve actually used.

Foxmarks – For people who want to access their bookmarks, regardless of where they are or which computer they are using, Foxmarks has the answer. It works in the background to save all those favourite links on a central server, and by either logging in with the Foxmarks plugin or using the web interface, those links can be easily accessed, wherever the user. Of course, privacy might be of concern here, although it seems to be possible to use a 3rd party server for storing links. I normally just move the entire Firefox folder around between computers (including all plugins, cookies, links, the full shebang), but this plugin might just change my habits.

Greasemonkey – Perhaps the most confusing and yet most useful plugin on the list, Greasemonkey takes a little explaining for non-technical users. Essentially, it allows users to write small pieces of script which can alter the appearance or function of a website or selection of sites. Whilst this might be beyond the average user, there is a nice repository of user-made scripts to browse and select from. There is a massive variety, but to give some simple examples from what I’ve sampled, the plugin can be used to alter currencies displayed on major websites, updated according to the exchange rate, change the display of images on websites or Google image search results, or add buttons to the display of a user’s profile on eBay to show highlight certain characteristics. A tweaker’s dream!

Sage – Probably one of the simplest and best plugins listed here, Sage is a lightweight RSS and Atom aggregator, which integrates nicely with Firefox’s Live Bookmarks facility. There’s not a lot to say beyond that, since it does what it says on the tin, and not a lot more. If I had one criticism, it would be the slightly clumsy method proposed for changing the way feeds are presented, although a nice little collection of styles is available, with instructions for using them.

SearchStatusThis is only a small plugin and might be disappearing from my plugins list soon, but it offers a neat little summary of roughly how popular a website is based on its search scores in Google and Alexa, amongst others, although it is aimed more at the search engine market than the average end-user. Note that the current version (1.18) caused a problem for me, whereby popup windows were incorrectly sized, depending on where the SearchStatus toolbar was situated.

Session Manager – If you’re always closing links accidentally, or shutting down Firefox without saving your bookmarks, Session Manager can act as your safety net. It will remember recently closed tabs and windows, and create a backup of your last Firefox ‘session’ to be restored after a crash or otherwise, and of course both of these settings can be tweaked to allow for saving a greater or smaller number of tabs or sessions. A very handy tool for the clumsy browser.

Smart Bookmarks – If you find you have too many bookmarks for Firefox’s Bookmark Toolbar, this simple little plugin has the answer. Put simply, Smart Bookmarks reduces the labels for bookmarks right down to their favicon.ico files, that little image which appears next to a web address in most modern browsers, with an option to have the bookmark name displayed when the mouse rolls over them. Although it isn’t universal, the plugin is compatible with a fair selection of custom Firefox themes, and this selection will no doubt expand. Using just a fraction of the size of an average bookmark name, that Bookmark Toolbar can now be comfortably home to a great many more frequently used bookmarks.

StumbleUpon – Just one more plugin that’s about integrating website functionality into Firefox, and this time for entertainment. StumbleUpon offers a way for users to randomly discover new websites related to their fields of interest, rate them, and submit new ones for others to peruse. The plugin simply integrates this into Firefox’s casing, and although the default setup can make the browser look more than a little clumsy, that won’t be the only reason you’ll wish you never installed it—that Stumble! button is a productivity killer!

Web Developer – Similar to the Firebug plugin mentioned above, Web Developer offers a context menu to access all of the wires and workings behind your websites, find problems and test new code. Its documentation isn’t quite up to standard yet, but the functionality appears to be there.

Of course, this is just a short sample of the plugins available, and Greasemonkey alone opens the door to thousands of others, not to mention the ability to integrate a variety of different search engines right within Firefox’s default context menus. Nevertheless, these are the ones I’ve come to have installed at this moment in time, some of which get installed by default whenever I install Firefox (such as Adblock, CustomizeGoogle and Sage)—others are merely enjoying their ‘trial’ period, and with such an active development community, I’ve no doubt they won’t be the last!