http://blogs.msdn.com/brad_mccabe/archive/2005/12/19/505664.aspxThe patterns and practices team has just released a new Composite UI Application Block. Below is a short summary, or you can get more information here . The Composite UI Application Block December 2005 Release is a source code-based component built onen-USCommunityServer 2.1 SP1 (Build: 61025.2)