The "Open On-Chip Debugger" provides JTAG/SWD access from GDB (or directly with TCL scripts) to processors with ARM and MIPS based cores.
See website for full list of supported targets.
The MSX emulator that aims for perfection.
NOTE: this project moved to GitHub. The content of this project page is frozen and will not be updated. The project is alive and kicking, though! Check out our website for the new project pages.