A new "product" is coming from microsoft, the Visual Studio Shell is a piece of software available for free for building over them your custom ide for your tecnology using an existing and tested foundation.
Visual Studio Shell is available in standalone or integrated mode, the standalone give you the possibility to distrubute your own ide without to have Visual Studio installed, with integrated mode you need to have Visual Studio installed but you have to use only one IDE, and on certain case this is the best choise, for more information go at
http://msdn2.microsoft.com/en-us/vstudio/bb510103.aspx
