Flock is a web browser that specializes in providing social networking and Web 2.0 facilities built into its user interface. Until the current version, Flock used the Gecko HTML rendering engine by Mozilla. Version 2.5 was released on May 19, 2009. The upcoming version 3 will use the Chromium rendering engine.
Flock is available as a free download, and supports Microsoft Windows, Mac OS X, Linux and FreeBSD platforms.