This is GDB, a source-level debugger intended for GNU, presently running under un*x. Before compiling GDB, you must set up links to five files according to the kind of machine you are running on. To do this, type `config.gdb machine', where machine is something like `vax' or `sun2'. This creates links named `param.h', `opcode.h', `pinsn.c', and `infdep.c'. Once these files are set up, just `make' will do everything, producing an executable `gdb' in this directory. About the machine-dependent files... m-.h This file contains macro definitions that express information about the machine's registers, stack frame format and instructions. -opcode.h, -pinsn.c These files contain the information necessary to print instructions for your cpu type. -dep.c Those routines which provide a low level interface to ptrace and which tend to be machine-dependent. (The machine-independent routines are in `infrun.c' and `inflow.c') About debugging gdb with itself... You probably want to do a "make TAGS" after you configure your distribution; this will put the machine dependent routines for your local machine where they will be accessed first by a M-period . Also, you want to make sure that gdb is not compiled with shared libraries on the Sun 4. And you want to make sure that you've compiled gdb with your local cc or taken appropriate precautions regarding ansification of include files. See the Makefile for more information. The "info" command, when executed without a subcommand in a gdb being debugged by gdb, will pop you back up to the top level gdb. See .gdbinit for more details. About languages other than C... C++ support has been integrated into gdb; it works, but somewhat buggily. Pascal support has not yet been integrated in gdb; the work is being done. About reporting bugs... The correct address for reporting bugs found with gdb is "bug-gdb@prep.ai.mit.edu". Please send all bugs to that address. About xgdb... xgdb.c was provided to us by the user community; it is not an integral part of the gdb distribution. The problem of providing visual debugging support on top of gdb is peripheral to the GNU project and (at least right now) we can't afford to put time into it. So while we will be happy to incorporate user fixes to xgdb.c, we do not guarantee that it will work and we will not fix bugs reported in it. For those intersted in auto display of source and the availability of an editor while debugging I suggest trying gdb-mode in gnu-emacs. Comments on this mode are welcome.