Debugging multi-process applications

[Mike Meyer]

    I am looking for information on multi-process debuggers currently being
    used in a Unix environment and also on ways people debug a multi-process 
    application in a Unix System V environment.  Has anyone had any experience
    with or heard of a multi-process debugger for a Unix  System V system?  
    Has anyone used the multi-process debuggers "cdb" or "pi" and what were 
    your impressions?

    Any information/suggestions in this area would be greatly appreciated.