IBM Rhapsody Modeler [^] Is a freeware version of their full blown product. I have worked for with the full-blown product 5 years. With it I designed/implemented systems using the code generator and model debugger (target languages c, and c++). Since UML has the concept of an "active class" the full-blown product is capable of generating multithreaded OS-adapted ready to run executables. Currently I use the freeware version (no code generator, no model debugger) to design and document designs in javascript and other languages. The freeware version has a simple report generator with which you can get .rtf files out of the model for audiences that are not technically versed. For others, since the tool is free, they can can use the model itself.