My Team has been using version 1.6 and now version 2.0 of the RadiantQ control to build a custom project management application in Silverlight 4.0, and the control has worked out great. The API is very straight forward, and when we’ve needed additional hooks into the control for automation, the RadiantQ team has been quick to respond to all our requests.

This is a truly a first rate control from a very responsive company. I definitely recommend it if you need a Gantt view anywhere in your application.