(Under construction.)
The Symbian C++ SDK and epocemx both support C++ development (see C page for details of how to get these).
The SDK integrates with Visual C++ 5/6 on a Windows machine to provide the capability of building MARM target applications of the EPOC machine and also variants to allow application debugging using the EPOC emulator for windows included in the SDK. Again it is possible to avoid VC++ and use conventional makefiles but with a loss of convenience and more importantly the VC++ IDE debugging tools.
The limited memory of (most) EPOC devices means that development of Eikon applications using the application framework classes provided by Symbian is not feasible with epocemx. The development of C++ console and non Eikon exes is feasible though along with OPX extentions for OPL.