I'm currently evaluating Javasript toolkits to migrate a fat client application to a webapp. So far dojo seems the best choice, really impressive work!

However we have one particular issue that needs to be sorted out fist: Unfortunately our app relies on various DirectShow ActiveX to display video streams (like Axis Media Control). This restricts us to IE, we have to live with that.

There's a problem with the overlay of DHTML elements over the ActiveX: Dojo DateTextBox flyouts, Dialogs and Popup-Menus are always displayed hidden the ActiveX.