The big story in the computer world recently is the release of Internet Explorer 9 and Mozilla's Firefox 4 within the same week. Both browsers were released to positive reviews.
As for how well they perform, I'd say the jury is still out and will be out for some time. As the web gets more complex, so do browsers and the programming languages that create the web. Rather than simple HTML pages with images, tables and links, pages are loaded with rich content programmed in Java and Flash, CSS layouts and text, rich graphics and a level of interactivity that wouldn't have been possible with dial-up age download speeds.
One of the biggest points contended by the new browsers is who can deliver the best HTML 5 experience, which is the new web standard in development by the W3 consortium of web developers. W3 is the keeper of the keys, so to speak, and it certifies any new technologies for browsers as well as the standards for the root programming languages of the web itself. It's an ever-expanding library of features, plug-ins and ports, and W3's job is getting extremely complex.
That's why it's taking so long to regulate and certify HTML 5 to its current advanced but still unfinished state, which now allows for things like embedded videos, additional page elements and applications that you used to need a Flash plug-in to interact with.
All browsers have some level of HTML 5 compliance but use different engines to render HTML 5 content. For example, Google Chrome and Safari are based in the WebKit standard, while Mozilla uses Gecko, IE uses Trident and Opera uses Presto. All approach the web a little differently - some platforms are faster, other render more elements or render those elements in a more elegant way.
Because it's relatively new, we're only starting to see rich HTML 5 sites that fully utilize the new standards, as well as the new CSS3 standards that go with it.
One example of an HTML 5 experiment is Arcade Fire's - excuse me, Grammy Award-winning Aracade Fire's - video for their song "We Used to Wait," where you put in the address of the home where you grew up and are treated to a Google Street View montage of said home while other videos and content pop in and out of other windows on the screen. If you haven't seen it yet, visit www.thewildernessdowntown.com to see what it's all about, and for a better understanding of why HTML 5 is such a big deal.
Another good site to visit is Mozilla's Web 'O(pen) Wonder gallery (https://demos.mozilla.org/en-US/), where different HTML 5 websites are showcased. Other sites to check out are www.html5gallery.com and www.101besthtml5sites.com, and if you do a search for "HTML 5 websites" you'll find dozens of compelling website galleries.