Add-ins extends the capability of the main program by adding enhanced custom commands and specialized features.
Add-ins may be downloaded from any of the following:
- http://msdn.microsoft.com/en-us/expression/jj873995.aspx
- http://www.webassist.com/go/xweb-add-ins
-http://www.expressionextras.com/products/lightbox.htm
- http://www.dotnetcurry.com/ShowArticle.aspx?ID=534
