The new Visustin v6 from Aivosto can create PDF flow charts from 36 programming languages. It reads the source code and "visualizes" each function as a flow chart.The idea is that this helps you to see how the functions operate. A "bird's eye" view gives a less detailed overview of a complex routine and viewing two charts side by side lets one compare different versions of a function.
Generating the flow charts from the code also means that they represent the actual code and not a plan for the code you should have written as such they should be an accurate visulization of what your app really does.
PDF support is new in version 6 and the ability to zoom makes PDF flow charts a convenient format for documenting even the most convoluted modules - although it is arguable that you shouldn't actually have any convoluted modules in a good project!
In addition to flow charts, Visustin creates UML Activity Diagrams and Visio flow diagrams directly from code.
A particularly useful feature is its support of a range of languages that are typically found in troublesome legacy systems - Cobol, MVS JCL, Visual FoxPro, Fortran, IAR/MSP 430 0, Ada etc. Having a flowchart generated from the code could well provide a good guide to exploring the overall structure and the deeper details of a difficult legacy system.
The complete list of supported programming languages is:
Supported operating systems:
Visustin runs on Windows 98/ME/2000/XP/2003/Vista/7.
A free evaluation version is available to download.