Flock The Social Web Browser - Version 2.0 Flock is an award-winning browser, built on Mozilla’s Firefox technology. Flock integrates over 20 popular sites so that you can be connected, not tethered, to the sites where your friends hang out. Share items, blog, upload photos, and receive email updates all from within your browser. The Flock browser is safe, free, and fun! Download today to find out why Flock won a Webby Award and was named #6 on PC World’s Top Products of 2008.