Jakob Nielsen once said that Flash is 99% bad. He goes to dispute that although multimedia has its role on the Web, current Flash technology tends to discourage usability for three reasons: it makes bad design more likely, it breaks with the Web's fundamental interaction style and it consumes resources that would be better spent enhancing a site's core value. Well Flash improved and was way up on accessibility and usability; Jakob even joined erstwhile Macromedia to work together to improve Web Usability and develop best practices for developing Rich Internet Applications.

And today, Flash is the new publishing tool of the century - Flash is now 99% Good. YouTube uses Flash. Flickr uses Flash. Google's finance pages generate stock graphs built in Flash. Newspaper websites use Flash to illustrate complex timelines or subjects. It's everywhere. So is the difference simply that the spread of broadband made Flash more acceptable, by cutting the delays while files load? Or have people worked out how to do more with it, and so enhance the web in ways they didn't before?

Flash has the advantage for the developer that the file created is self contained, and doesn't rely on the browser it's viewed in. As the software designer Jacek Artymiak puts it, Flash "is, in a way, the PDF of interactive multimedia. Both formats are so popular because, for the end user, the efforts that go into achieving the desired results are minimal."

Flash's ubiquity is one major reason for the success of flash. It is secure and there are no security flaws in the Flash Player except for one outstanding one at Secunia which is rated "less critical" (which has been patched anyway). To content providers, meanwhile, Flash is a one-way medium: you don't find file-sharing networks full of videos or songs ripped from Flash files.

Read the Guardian's full interview of Mark Anders, the senior principal scientist at Adobe Systems, who is in charge of making Flash "a great platform for building the next generation of rich internet applications".