The .NET framwork keeps on growing and so does the size, so it has become apparent that a lighter version of the .NET Framework is needed. Last week, Microsoft released the Visual Studio 2008 and .NET Framework 3.5 SP1 Beta. This includes the .NET Framework Client Profile,a smaller, optimized verson of the .NET framework needed for clients applications to run.The size of this framework is approximatley 27 MB (not that small), some of the assemblies that still lies in the beta but will be removed in the RTM version are System.Management, System.Messaging, System.ServiceProcess, System.Web, System.Web.RegularExpressions Visula Studio 2008 also has an option where you can make sure that an application targeted for the Client Profile Framework does not reference assemblies that are not included in the Client Profile Framework.You can have a look at the list of assemblies that are inluded in the client profile here