When "virtual hosting" company Joyent threw open the source code for its Connector suite of collaboration tools earlier this month, it garnered hardly a whisper in the tech press.

Among developers, however -- particularly those working in the "Ruby on Rails" Web application framework -- it was cause for modest celebration.

Offering team e-mail, calendars, bookmarks, contacts, files, and basic Web hosting, Connector is a collection of inexpensive Web-based tools designed for individuals, small businesses or project teams. It represents a new wave of what some IT-productivity thinkers are calling "Office 2.0" applications. These apps are moving beyond the basic functionality of Microsoft's dominant Office and Outlook programs to what one venture capitalist and Joyent fan has called "purpose-driven applications" -- ones that focus on real-world user needs for communication, organization, and content management. And it's part of a range of open-source, "open-services" products that Joyent CEO David Young -- who bills his company as a new kind of platform provider for a new era of business computing -- believes will transform the way companies use, store and manage data and the way they build specialized applications.

"We take away all the pain, all the unpleasant parts of running a Web-based business," said Young. "Unlike the traditional hosting companies, with us you can start really small and rapidly grow to support hundreds of thousands of users, while paying only for what you need."

For an 18-employee company based in a nondescript office in Sausalito, Calif. across the Golden Gate Bridge from San Francisco, Joyent (which was founded by Young and partner Jason Hoffman in 2004) has some fairly well-known customers, including the Los Angeles Times and Major League Baseball. Its poster-child client, however, is Twitter.com, the instant-update social networking service that allows users to post brief (140 characters or less) messages to the Web from virtually any device with a cellular or Internet connection.

To anyone over the age of 25 Twitter is inherently abhorrent -- author Clive Thompson called it "blogging taken to a supremely banal extreme" in a recent Wired article -- but it has grown rapidly since its March 2006 founding, doubling its users every two to three weeks according to its founders.

Twitter is thus a prime example of a "red-shift" company -- one that is experience geometric growth in demand for data processing, according to the definition by Greg Papadopoulos, CTO of Sun Microsystems, which is the primary supplier of hardware to Joyent.

Twitter started at Joyent with a $15-a-month subscription and has rapidly scaled up its requirements as it has caught fire with the high-school and college set. For startups -- or for big companies wishing to move into new Web-based ventures -- Joyent's pay-as-you-go model "reduces tremendously the cost of experimentation," said Jason Hoffman, co-founder and CTO.

"Companies don't have to undergo the time and expense of building up their infrastructure to try something new," Hoffman explains. "They can just say 'Let's try this, if it doesn't work, we'll scale back. If it does, we'll spin it up.'"

Young said that revenues from Accelerator, Joyent's on-demand infrastructure subscription service, are increasing at 500% yearly. That success has been sweet music to Sun, which made the source code for Solaris 10 available for free in March 2005 and has gone even further in embracing open-source and shared-infrastructure or "utility" computing since Jonathan Schwartz succeeded founder Scott McNealy as CEO last year.

"The open sourcing of Solaris allows us to exist," said Young, "because it enables us to do a lot of virtual scaling."

Like many red-shift prophets, Young sees the spread of utility computing as inevitable.

"I'm willing to acknowledge that if you're Google you should run your own infrastructure," said Young. " If you think you need to fly your own 737, go ahead do that. But most of us have to fly coach. And in that case you should come to us."