Question Free tabbed MDI control targeted for .Net 4

[cjyap]

Hi,
Is there any free tabbed MDI control targeted for .Net framework 4.0?
I found a few on the Internet like

tabbed MDI Window manager available at https://mdiwinman.codeplex.com/
dockpanel suite available at DockPanel Suite | SourceForge.net
but all of them targeted for .Net framework 2.0.

Any suggestion?