Yahoo is opening Manhattan to a small group of Javascript developers this week, and it will be made more widely available "when it's ready," Fernandez-Ruiz said. Developers can also deploy Mojito apps in any other environment that supports Node.js, such as Amazon Web Services, he said.

Yahoo has struggled to compete with Google and to return to the Internet leadership position it once held. It's had several and is to be a takeover target. That could make developers wary of jumping on board a new platform from the company.

But Fernandez-Ruiz argued that developers can have confidence in the project because it is open source. Should Yahoo's support for Mojito ever waver, the code would still be available for development, he noted.

IDC analyst Karsten Weide said Livestand "is beautiful, it's fast, and it's HTML5, so it's cutting-edge technology." He called the app's offline functionality "one of the big upsides." But Weide suspected that Yahoo was open sourcing the Mojito framework that Livestand previewed because "it did not get the distribution that [the company] had hoped for on its own steam."

Mojito is available from the GitHub open-source repository at .