"We wanted to pick applications that would provide utility and help the productivity of our users," says Mario Sundar, the Community Evangelist at LinkedIn. "The technology behind our partners [who provided applications] had to be well-proven before we added them."

LinkedIn added nine applications in total, all focused on helping users share business information with their colleagues and contacts, known on LinkedIn as "connections."

Google, for example, provided its Presentation application, allowing LinkedIn users to share PowerPoint-like presentations from a meeting or tradeshow with their connections. Amazon offers an application that allows users to share what books they've been reading with their connections.

Keeping in line with its business focus, LinkedIn has employed a conservative strategy around adding third-party technology, a departure from its consumer-oriented competitor, Facebook, which to date claims has more than 24,000 applications on its platform. Though that number sounds staggering, the majority of third-party Facebook applications cater to entertainment interests (such as games) rather than business productivity.

To shield itself from the liability associated with its wild west ecosystem, Facebook offers sweeping disclaimers in its terms of use that essentially absolve the social network from being held responsible for what third-party application providers do with user information.

LinkedIn appears adamant about not overwhelming its professional users, who tend to be far less playful than the Facebook community. Sundar says that the company will ensure its applications don't violate the privacy of its users by making them pass a vigorous vetting process before they become publicly available on the site.

Though LinkedIn applications may access the information on user profiles, including connection lists, Sundar says that user email addresses will not be made available to third-parties, preventing the possibility they spam users with product pitches.

"Privacy practices are a critical point of the integrity of the applications, " Sundar says. "When you come to the professional space like ours, it's so important."

According to Jeremiah Owyang, a senior analyst at Forrester Research who examines social technologies, one of the upsides to LinkedIn's new applications is that they expand the area in which a business person can collaborate and share information; it's no longer limited to the company intranet or the cumbersome process of sending multiple e-mails.

"You can collaborate with your colleagues at a company and, even beyond, with your business contacts [from other companies]," Owyang wrote in his blog on web strategy. "Imagine that, getting work done with people that aren't even your colleagues."