MLC++ interfaces dot and dotty from AT&T []. These programs allow you to display graphs on the screen and to generate postscript for printing and inserting into documents.
A web server is available to download graph viewing tools. You can obtain precompiled binaries and source for dot, dotty, and some associated programs. The URL is http://www.research.att.com/sw/tools/reuse/
Click on source or binary. If you accept the no-cost non-commercial license, then you'll be presented with a form to fill in, and then finally hotlinks from which to download the archives.
Please direct dot/dotty related questions directly to Stephen North (north@research.att.com).