Adebug/Assemble is a pair of Debugger/Assembler for the MC68Xxx family running on Atari and Amiga computers. Years ago commercial product, now GPL.
Graphical debugger interface for the Bochs PC emulator.
Tools to incrementally build customised Forth Virtual Machines for embedded applications. Token compiler converts token description into C code templates. PC console application includes FVM, it is used to compile and debug bytecodes for target FVM.
A cross-platform wxWindows class for running Ghostscript and manipulating the image it produces, plus an IDE/debugger for developing programs written in PostScript. For a PostScript debugger, there is now also an Eclipse plug-in - see http://thomas-fritsch.github.io/psdt/
Oracle client side tracing and monitoring utility
A simple (complete) embedded system tool chain system.
The XPS is a scalable platform for meta-programming and domain engineering. It provides a virtual machine, compiler, and runtime library that make it possible to efficiently develop, debug, and run programs based on XPL (eXtensible Programming Language)
The dude is a UNIX debugging package independent of the ptrace() system call; it consists of a kernel module [the_dude.o], a library to interface with the module [libduderino.so], and an ncurses client [ddbg] .