SAN FRANCISCO - Following the lead of more playful Internet hangouts, LinkedIn is trying to enliven its website's office-like atmosphere by offering online programs made by other companies.

Eight external applications debuted Wednesday on LinkedIn, nearly a year after the Mountain View, Calif.-based company announced its intentions to welcome outside contributions.

By drawing upon other programs, LinkedIn hopes to become a more compelling place to keep in touch with business contacts or mine career opportunities. The privately held company generates revenue through advertising and subscriptions sold to employers, head hunters and sales representatives who want more access to LinkedIn's membership.

More than 30 million people worldwide have set up profiles on LinkedIn, which has positioned itself as an online network for taking care of business, as opposed to the frivolous pursuits that permeate Facebook and MySpace.

Having fun has proven more fruitful so far. Both Facebook and MySpace boast more than 100 million members, helped by an array of outside applications that enable people to play games with each other or share music and photos.

What's more, privately held Facebook boasts a $15-billion market value, based on a $240-million investment that Microsoft Corp. made a year ago. LinkedIn's market value has been pegged at about $1 billion, based on stakes that were sold for nearly $76 million in two investment rounds this year.

LinkedIn is treading carefully as it ushers in outside programs. The applications have to be appropriate for professional settings and are being screened to guard against some of the security loopholes that have plagued some outside programs designed for Facebook and MySpace.

The first crop of LinkedIn's outside applications include a file-management system from Box.net, business presentation software from Google Inc. and travel itinerary tools from Tripit.

The new applications aren't necessarily all about business. Amazon.com Inc. is offering a program that will let LinkedIn members share book recommendations. There are also blogging tools, including one made by Six Apart Ltd., whose board includes LinkedIn founder Reid Hoffman.