Debuggers:

Port: acpicatools
Path: /usr/ports/devel/acpicatools
Info: Some utilities for Intel ACPICA (Debugger, ASL Compiler and etc.)
WWW: http://developer.intel.com/technology/iapc/acpi/index.htm

Port: ald
Path: /usr/ports/devel/ald
Info: Debugger for assembly level programs
WWW: http://ald.sourceforge.net

Port: cgdb
Path: /usr/ports/devel/cgdb
Info: A curses-based interface to the GNU Debugger
WWW: http://cgdb.sourceforge.net/

Port: ddd
Path: /usr/ports/devel/ddd
Info: Data Display Debugger -- a common graphical front-end for GDB/DBX/XDB
WWW: http://www.gnu.org/software/ddd/

Port: kodos
Path: /usr/ports/devel/kodos
Info: The Python Regular Expression Debugger
WWW: http://kodos.sourceforge.net/

Port: ups
Path: /usr/ports/devel/ups-debug
Info: X based source level debugger for C, C++, and Fortran
WWW: http://ups.sourceforge.net/

Port: bfe2
Path: /usr/ports/emulators/bfe
Info: X11 GUI for the bochs debugger (revision 2)
WWW: http://bfe.sourceforge.net/