EiffelStudio O-O Programming Suite for Mac OS X

name_already_in_use writes "Eiffel Software released their object-oriented programming environment for Mac OS X. It is a powerful language offering all the usual O-O wonders as well as few unique features of it's own (Design by Contract, generics). All compiled code can be run on multiple platforms including Windows, Linux, Solaris, and of course now Mac OS X, so there's no need to re-write code for different architectures."