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.
BEYE (Binary EYE) is a free, portable, advanced file viewer with built-in editor for binary, hexadecimal and disassembler modes. It contains a highlight AVR/Java/i86-AMD64/ARM-XScale/PPC-64 and other disassembler, full preview of MZ,NE,PE,ELF and other.
A disassembler and a simulator for the MSP430 CPU. Both programs only read TI-TXT files. Licensed under the Simple Public License (SimPL) 2.0. For full license information, please read license.txt. Compiled executables are available for Windows and Mac OS X. Linux users will have to compile their own binaries. Instructions for compilation are included in README.txt.
A Qt-based GUI is available for sim430. Binaries only for OS X, for now. Source files can be found in src/qt folder.