MySpace on Thursday launched in beta the second phase of its developer platform by allowing software makers to test their applications on members of the social network.

With the launch of the Application Gallery, developers will be able to offer their work to MySpace members, who can choose to embed the applications on their profiles and home pages. In listing the available applications in the gallery, developers also will be able to share the software with other developers.

Early last month, MySpace opened its network to developers by providing the tools needed to build commercial applications that can run on the site at no charge. In return, MySpace hopes the new applications will keep subscribers on the site longer, which makes MySpace more valuable to advertisers. Rival Facebook launched in May its software tools for developers.

Since the February launch, about 5,000 developers have been building and testing applications in the MySpace sandbox, which is a closed environment. Applications built so far are in a variety of categories, including music, movies, and TV; politics and causes; quizzes and polls; and video, MySpace said.

Once members have installed their first application, they will get one-click access to the Application Gallery from their home page through the control panel. Applications will have their own profile page, similar to MySpace user pages. MySpace members only have to use a "click to install" button to embed the software on their profile or home page.

MySpace developer tools include the Google-developed OpenSocial set of application programming interfaces. The APIs are for building apps in JavaScript and HTML that can be hosted on any social Web site. Other companies implementing the technology include Engage.com, Friendster, Hi5, Hyves, Imeem, LinkedIn, Ning, Oracle, Plaxo, Salesforce.com, and Six Apart.

At the end of 2007, MySpace accounted for more than three-quarters of the Web traffic to social networks in the United States, according to Web metrics firm Hitwise. Facebook was a distant second with 12.6%.

MySpace visitors on average, however, spent about 30 seconds less time on the site than a year ago. Facebook visitors, on the other hand, spent about 10 minutes longer on average, according to Hitwise.