MySpace will open the doors of its developer Web site on Tuesday and make available there the necessary tools to build applications for the world's most popular social-networking site.

Developers will have about one month to familiarize themselves with the development tools and create and test applications before MySpace begins letting its members install them early in March.

"Developers will be able to build applications, but they'll be in the sandbox environment where consumers won't be able to see them," said Kyle Brinkman, vice president and general manager of platform for MySpace.

With the opening of the developer Web site, MySpace gets closer to catching up to its main rival, Facebook, which opened its platform to external developers in May.

For Facebook, despite some bumps along the way, opening its platform has been overwhelmingly positive. More than 14,000 applications have been created for the site, which in turn has increased its attractiveness to current and potential members.

MySpace isn't alone in following Facebook's lead, as most major social-networking site operators have decided to open their platforms to external developers as well.

In addition to the individual developer platforms, Google unveiled in November its OpenSocial project, which aims to provide a set of common APIs for social-networking operators to adopt so that applications built with those APIs will work across multiple sites.

To make sure that the applications are safe to use, MySpace will test all of them before making them available to its members, Brinkman said.

Developers will be able to generate revenue from their applications by placing advertising on their applications' "canvas" pages, where members manage the applications they install. Developers will get to keep 100 percent of the advertising revenue generated on canvas pages, Brinkman said.

Developers can choose to run ads from third-party ad providers as long as the ads conform to MySpace policies, such as not containing pornographic content. Moreover, MySpace will let developers run ads from two new ad services that it is beta testing and that it plans to launch at a later date called HyperTargeting and SelfServe, Brinkman said.

In addition to the canvas page, applications will also be featured on their own profile pages, where developers will be able to explain in detail what each application does and how it works. Moreover, there will be a gallery where the applications will be listed. Of course, the applications will also appear on the profiles of members who install them and on members' MySpace home pages.

MySpace will make available three types of APIs to developers: Google's OpenSocial APIs with MySpace extensions for building applications in JavaScript and HTML; ActionScript to build Flash applications; and REST (Representational State Transfer) APIs for applications that require server-to-server connections.

Applications will be able to make use of data on MySpace profiles, but they will be governed by existing privacy controls that apply to members.

The MySpace Developer Platform site will also include documentation, sample code and discussion forums.

Also on Tuesday, MySpace will launch a blog geared toward developers, where MySpace staffers will post relevant information and news about the program.