I'm starting in on re-writting our main desktop application from VB6 to .NET and want to use WPF. Now our legacy app is an MDI app and we need to maintain the flow/look as we have hundreds of agents that use it and re-training needs to be minimal to non-existant.

Anyone have any good solutions to maintain an "MDI" appearance / functionality? Its a large application so like with VB6's limit of 255 controls on a form (it has the control array thing to bypass it) and resource intensiveness should take some consideration here too.

Ive see using frames as one possible solution but I think it will be too heavy and would rather use separate "chjild" forms.

Thanks