Fresh off a stellar second quarter earnings report, the professional social network LinkedIn has today released new developer tools and resources in an effort to stimulate application development and supply its service with enough content to keep members continually engaged on its web and mobile platforms.

Above: LinkedIn sign-in experience

In the form of developer tools, LinkedIn has released a refreshed sign-in with LinkedIn experience, a reworked share API to give developers more exposure on LinkedIn, and a cleaner, simpler developer website. The company has also revised its developer terms of service.

Specifically, the sign-in experience, which appears to be modeled after the screens used by Twitter and Facebook, has been improved with a new design and enables developers to request email addresses from the people who want to log in with LinkedIn. The screen now shows users exactly what types of data the application in question may access. The upgrade should encourage more publishers and mobile app makers to add a log in with a LinkedIn option.

The spruced-up share API is equally important as it gives approved devlopers exposure inside LinkedIn. The API has been updated with an attribution element so that should a LinkedIn member opt to share a piece a content to the site, the publisher will receive credit in the form of a “via” link listed atop the post.

The message from LinkedIn today is this: Come build your media-rich applications on LinkedIn and integrate with us, and we’ll put your content in front of 175 million people. In return, LinkedIn gets content flowing into its network that should further engage its members who, especially on mobile, are consuming it even more rabidly with each passing month.

Head of API platform product and strategy Madhu Gupta summed up the intent of the changes: “We’re now making it even easier for our developer community to use LinkedIn as their main distribution platform for discussing and sharing professional content.”

You can read that statement as LinkedIn wanting to be the single place where business folks go to get, discuss, and share news. And really, this is all about content, as evidenced by developer tool launch partners WordPress, Flipboard, and Business Insider.

Content will be the thing that keeps LinkedIn relevant on mobile. CEO Jeff Weiner said as much to investors last week. Content is driving especially high engagement rates in LinkedIn’s iPad application, where the company is starting to experiment with advertisements, he said. “We are seeing encouraging signs of engagement as more than half the page views on the app are being generated by content-focused products such as updates, news and groups.”

LinkedIn also wants to be seen as having a platform as robust as any other. Twitter and Facebook, even amid a wave of recent criticism and growing tension with developers, sit very much atop the platform hierarchy. LinkedIn’s platform offerings seem at best tertiary when pitted against Twitter and Facebook, which have their sign-in buttons embedded everywhere.