http://blogs.msdn.com/b/eric_carter/archive/2007/04/11/infopath-2007-and-vsto-2005-se-or-vsta.aspxInfoPath is a great tool in the VSTO toolkit. There are two ways you can write managed code behind an InfoPath form. First, you can use Visual Studio Tools for Applications which ships on the Office CD with InfoPath 2007. VSTA provides a nice integrateden-USTelligent Evolution Platform Developer Build (Build: 5.6.50428.7875)