Hacked this up a while ago and while it is probably not going to get to the point where it is really usable...it might help someone else's efforts. It uses 100% IronPython and four DLL's that do most of the heaving lifting:
Nini for saving settings in an INI file. ICSharpCode.TextEditor for the editor control. WeifenLuo.WinformsUI.Docking (Dockpanel Suite) for the docking. MdbgCore.dll (Microsoft's managed debugger) for the debugging support.
Sadly - I think this will not work on Linux/Mono as I believe that the Docking dll and maybe also the text editor will not work there. (Certainly the Managed debugger has zero chance).