The service isn't quite open to everyone, however. Current beta testers can now invite as many people as they wish to join the service, but those without connections will have to wait a few days.
Previously known as The Venice Project, Joost offers over 150 channels of video programming that spans a variety of genres. Most of the programming is available to U.S. viewers. Joost expects to make more shows available to international users in coming months.
Starting today, the company expects to run commercials from some of its 32 advertising partners, including The Coca-Cola Company, HP, Intel, and Nike.
"Today marks the beginning of an exciting phase for Joost " we are officially open for business," said David Clark, executive VP of global advertising for Joost, in a statement. "We're enabling our viewers to share Joost with their friends and family, and we're working collaboratively with the world's leading advertisers and agencies to design a new ad model for the next generation of television."
Joost is the brainchild of Janus Friis and Niklas Zennstrm, who previously founded Kazaa and Skype. As a downloadable video player, it can be seen as a bellwether for rich Internet applications (RIAs).
Many companies are developing RIAs to compete more effectively against browser-based services. RIAs are appealing to businesses because they offer greater control of the user experience and of the screen real estate than services that depend on a Web browser, which may be infested with toolbars and other distractions that compete for user attention.