Firefox 3.5 was officially released yesterday. If you’re already running Firefox 3 you should get prompted to upgrade in the next few days – but if you want to expedite matters you can choose “Check for Updates…” from the Help menu.

As there are quite a few Linux users who find this site, I’ll point you in the direction of this post about how to install Firefox 3.5 on Ubuntu. Alternatively you could just make do with Firefox 3 until the release of Ubuntu 9.10 in October. Users of other distros will have to search for instructions themselves, I’m afraid.

If you’re not running Firefox at all – or you’ve got a really old version – you can download the whole thing from firefox.com

So what’s new in Firefox 3.5? In short, loads! I think that this is one of the most exciting browser releases from any vendor in quite some time. For years the web has stagnated due to old standards, but recently browser vendors have started to add new features which will really drive the web forward, not just as a content delivery platform, but also as an application platform. With more and more services becoming web based, additional browser functionality translates into more powerful applications.

Apple, Opera and Mozilla have been pushing the web forward with new technologies for a while now, but there wasn’t much integration between the disparate features. You could use SVG for vector diagrams, or draw to a bitmap using the Canvas element. But each technology was separate – a stand-alone rectangle in an HTML page.

With Firefox 3.5 there is much more integration between these new technologies. The native video playback has been fairly widely publicised – but some of the best demos include pulling video frames into a canvas element for further processing, playing a video within SVG content to allow it to be stretched and scaled, or using SVG filters and masks to alter the display of your HTML content. SVG and canvas move from being self-contained mechanisms for drawing to the screen, and instead become another tool that HTML authors can wield in order to produce interesting results.

So with that fawning out of the way, here are some links to a few technical demos which show off some of the new features of Firefox 3.5:

• A whole load of different techologies mixed on one page
• CSS3 demos here, here and here. These show off downloadable fonts, drop shadows, rounded rectangles and multi-column layout
• SVG clipping masks applied to HTML content (mouse around a bit)
• Not specifically a Firefox 3.5 demo, but it does help to show off the faster Javascript engine: Liquid image resizing using Javascript
• Using the new Audio element to produce a plugin-free audio player

One of the most impressive new additions is the Video element – which allows for native playback of video files within the browser. This means no Flash plugin is needed, and the content is more accessible to scripting. Unsurprisingly there have been a number of demos showing the kind of things you can do with video as a native object:

• SVG clipping and filters applied to a video
• Dailymotion’s HTML5 video demo
• Video, CSS3 transforms and SVG
• Javascript, video and canvas powered green screen effect
• Javascript, canvas and video to produce dynamic content insertion into a running video
• Dynamic subtitles
• Javascript, video and canvas motion tracker

There’s some pretty cool stuff going on there – and these are just the technical demos. Now that 3.5 has been released, I’m sure we’ll start to see some very interesting uses for these new technologies.

One final thing – it’s not a new feature, as such, but an improvement to an old one that didn’t quite make it into Firefox 3. You may have noticed the appallingly named “Awesome Bar” in Firefox. Yes, to you and me it’s just an address bar that also searches your bookmarks and history – but to a marketing department that’s “awesome”. Anyway, in Firefox 3 it usually presented you with pretty good results in the drop-down list, but there was no way of controlling those results – to only show bookmarked pages, for example. Well, now there is.