>>Has anybody tried it? And if it's not advisable, what's the alternative organization for a transaction based (desktop) application that requires a large amount of different forms? Tabcontrol will only allow a limited amount of different forms, and the forms cannot be viewed simultaneously.
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>>And if I do insist on mdi, I'd better go WinForm than WPF?
>
>I use MDI with WinForm when needed. I try to limit its use to cases where the user thinks that it will be helpful.
>However, implementing it is disarmingly simple

Thanks. I used MDI in WinForm as well. It's as you said rather easy. I found that the WPF.MDI package works too. Haven't found how to get the children in the center of the MDI yet though ;).