A preview of the new Flock browser, built on the Mozilla project codebase, was released late Friday afternoon.
Flock adds some of the most popular tools from social networking sites: Users can tag bookmarks instead of creating hierarchies of folders devoted to different topics, and the browser is integrated with del.icio.us, a service for storing and sharing Web bookmarks, as well as Flickr, Yahoo's photo management/sharing service. Users can install alternative services, and the company plans to continue to integrate with others.
Blog posts can be created and posted from within the browser, while a sidebar called Shelf acts as a repository for blogging content, such as photos and text; items on the Shelf can be dragged into place on the blog post.
In a FAQ, Flock said 100 percent of the current code is available under the GPL license, and that the plan is for most of the code going forward to be open-sourced.