If 50% of what this Wired article says is true, your Web experience will never be the same again.
Flock advertises itself as a “social browser,” meaning that the application plays nicely with popular web services like Flickr, Technorati and del.icio.us. Flock also features widely compliant WYSIWYG, drag-and-drop blogging tools. The browser even promises to detect and authenticate all those user accounts automatically. It’s a clear attempt to be the browser of choice for the Web 2.0 user.
Yes it is Free Software.