I recently discovered how to use Eclipse for doing development with ARM processors. It is actually fairly simple to configure: It requires downloading a plugin for C/C++ development, and then modifying which compiler and linker are called (using arm-...-gcc over just gcc). I wonder if anyone has tried to configure RL78 development using the compilers that come with the IAR workbench. IAR's C compiler and linker is in the bin directory, iccrl78.exe and xlink.exe respectively. I am sure with the right configuration it would work properly, substituting those compilers and linkers for the default gcc. I don't necessarily know how debugging and memory mapping would work, since those would have to be specific Eclipse plugins, but I really love the Eclipse development environment.