The deal includes two initial "webisode" projects inspired by CosmoGIRL! and Popular Mechanics. The online series will feature a number of two- or three-minute episodes that will launch on the magazines' websites.
The CosmoGIRL! project is a serialised soap, with fans submitting suggestions about what should happen next in the story.
Fox and Hearst will share any ad revenue equally. If successful, they hope to create further content for both broadband and network TV.