michael@0: js/jsd contains code for debugging support for the C-based JavaScript engine 
michael@0: in js/src.  jsd_xpc.cpp provides an XPCOM binding for the library.
michael@0: 
michael@0: js/jsd/jsdb is a console debugger using only native code (see README in that 
michael@0: directory.)  This debugger is no longer being actively developed, though it
michael@0: should work.