This is cool.
In our Mozilla Reverse Engineering Project, we are trying to extract architectural information from the publicly available Mozilla (Netscape) source code. Here's what we have done so far:

The C source files of Mozilla were parsed using our C parser cparse. The 4-tuple RSF output for each file was stored in a separate file.
All the RSF files were fed into sortrsf, to eliminate duplicate tuples and sort the tuples for faster processing.
The htmlrsf utility was used to create a HTML version of the Mozilla source code with hypertext cross references and a 3-tuple RSF file for use with rigiedit.
In ongoing work, the graph editor rigiedit is used to identify and extract subsystems of Mozilla.
Rigi Projects: Mozilla Reverse Engineering