The only frame window class MFC for Windows CE supports is CFrameWnd. Windows CE doesn't support multiple document interface (MDI).
MFC for Windows CE supports nine new member functions you can use to create and manipulate command bars. A command bar is a new common control, unique to Windows CE, that combines the functionality of a menu bar and a tool bar, and also supports the standard Close (X) and help (?) buttons in the upper right corner. Using a command bar instead of a title bar, a toolbar, and a menu bar conserves a lot of screen space, which is important on devices with small displays.
For more information about command bars, see Command Bars in the SDK documentation.
MFC for Windows CE fully supports the CSplitterWnd class.
To see where the frame window and splitter window classes fit into the Windows CE class hierarchy, see Window Class Categories and Classes Derived from CObject.