Interview: Firefox 3's interface design guru talks

"Right now, if I load Tripit.com, it knows that I am in Mountain View even though it knows I live in Toronto. If we can pull that information into the browser, we can use that information for things like a map search, so when I search for Starbucks it doesn't show all Starbucks across North America, it shows me the Starbucks based on where the browser knows I am – and inferred from other information.

"So there is a lot of rich metadata that we see on the client's web browser letting us infer things like location, modality, and even security – knowing whether you are in a public or private place.

"Obviously we can tie into even richer things like GPS services, and we're looking at ways of wrapping native services on mobile devices using a little bit of JavaScript so we can expose that both to ourselves and to websites.

"Websites will be able to run things like 'get user location' and it will return some sort of standard ISO location information that they can then use to provide more relevant information to users. We're looking at different ways of doing that. We really think the important thing here is opening up the mobile space and offering these services to programmers.

"I can picture a future when a phone is just a device that runs JavaScript, DHTML, HTML and all of the applications – your browser, your dialler, and your IMclient. They are all little web programs, the same things you use in your web browser, but running on your phone and interoperating and exchanging information."

By that do you mean the Google Android model?

"I'm not as familiar with the Android model, and the SDK is partially open but not fully open, so it's hard to deem how they will pass those messages around. For Android, I believe most things have to be written in Java, but not necessarily JavaScript.

Google is right next door: how much do large technology companies influence your projects?

"We view them as partners and collaborators in a lot of cases. In cases where what they are trying to do increases the power and reach of the web, we're really thrilled to be working with them, and they've got a lot of great ideas.

"For example, with Firefox 3 we have been really working hard on trying to solve the problem of malware. The way we have been doing that is we've got this local blacklist of malware sites that we're checking every 30 minutes, and Google is scanning the web to find malware sites. We work with them to make sure that if they ever block a site, there is a button there that says, 'why was this site blocked?'. It's actually going to tell developers exactly what was wrong with that site and where the site has been infected with malware.

"In a lot of cases, people don't even realise their site has been hacked. We actually had this happen to us in Beta 3. We turned on the malware feature and a well-known web developer, Joe Hewitt, had his website blocked. And people assumed it was a bug because Joe is a really good guy and he is not going to host malware knowingly.

"It turned out he was running an older version of WordPress and he didn't know it, so when he looked into it he found out that his site was hosting malware. And because of that, he was able to get it cleaned up. So that's a tangential answer, but it's an example of where we are working with people, and we influence them just as much as they influence us."