I have a working prototype of a Case tool that I'm calling "flower" for now. It's written in Eiffel, and used Tcl/Tk for the GUI layer. I'm developing it under Linux, but it should run under any platform that supports the ISE Eiffel environment and Tcl/Tk (Tcl version 7.4, and Tk version 4.0). As soon as Tck/Tk are available for Windows/NT, this tool should work there. It should port to TowerEiffel and SiG's compiler without much effort.
The prototype is still a little rough around the edges, but it can be used to edit diagrams, and it supports loading and saving them. It supports a subset of the symbols on a Rumbaugh class diagram (Class, Association, Aggretation, and Generalization). Here's some of what it doesn't support:
Linux binaries are available here, or perhaps in ftp://ftp.crb.oslo.no/pub/Linux/utils/flower_bin.tar.gz. The source is available here. Finally, here is a sample diagram.
If you've taken a look at Flower, I'm like your feedback. I'd like to know:
I can be reached at billf at jovial dot com.