A complete C++ Text User Interface (TUI) featuring windows, dialogs (buttons, check and radio boxes, input boxes, etc.), mouse support, menues, etc. It's available for various platforms and compilers.
DLDialog offers the capability to draw a variety of widgets. It includes a definition language similar to Tcl/Tk. It can display dialogs the tvision/ncurses interface or using graphical windows with the QT/X11 interface.