dSymbolizer lets you easily to decode a backtrace from a stripped application on Mac OS X by matching it with an external symbol file (dSym). This is possible to do manually through GDB, but dSymbolizer makes it less of a chore.
GBA Debugger for Mac OS X and GNUstep
99eyeballs is a tool that helps developers using Mac OS X Apples Cocoa frameworks find inconsistencies in the retain count of Objective-C cocoa objects.
Tools for Palm OS developers on Mac OS X. Cocoa Palm Reporter logs traces emitted by the Palm OS Emulator. USB-TCP Bridge provides a socket that can be used to communicate with a Palm handheld over USB (for example, GDB).
CUT is a simple, to-the-point unit testing system. It's different from other unit test packages in that it follows the KISS principle. It's designed for C testing, not designed to emulate SUnit.
A pluggable view that can easily be added to any application that utilizes sqlite3 in their iPhone application. Allows for real-time display and modification of data and table structures.
Code-dump is an Objective C program that decompiles PPC Objective C programs on Mac OS X, relying on their inherently structured format.
A program to apply a link map to a Mac OS X crash log that came from a build without traceback tables. The output contains at least as much information as would the same crash log from a corresponding build with traceback tables.