Facing a blitz of new operating systems for a new generation of smartphones that are already unchaining Web users from their desks and lightening the load on their laps, the open-source folks at Mozilla sped up their work on Firefox 3.5 and are formally releasing it today, touting it as a major upgrade. And the new release does seem markedly faster and better.

"The Fantastic Firefox: Why Mozilla's new browser augurs great things for the Web," Slate's Farhad Manjoo gushes. Other reviews are also good. And my own experience so far backs that up.

With smartphone users increasingly burdened by proprietary operating systems for iPhones and Google and Palm devices, among others, Mozilla's open-source approach keeps laptops friendly and free of fees and contracts. How much longer laptops will be the Web device of choice, though, is up for debate.

Mozilla's a mostly non-profit crew (intentionally). On the other hand, Firefox is no MySpace, which is being overwhelmed (just as monetization of social-networking sites is just around the corner) by Facebook and YouTube and Twitter.

Mozilla's not likely to be left in the dust during this current monumental shift from notebooks and desktops to handheld Web access. Google, which knows how to make money, is unlocking its smartphone Android software, which opens the door much wider for development and spread of Mozilla's mobile Firefox version, Fennec.

Microsoft's Internet Explorer 8 is a snorer on regular computers, and a it probably will continue to be dull on smartphones as time goes on. But even on laptops and desktops, Firefox faces a host of "new challengers," says CNET's Stephen Shankland:

Mozilla's Department of Evangelism is hard at work.