So I want to know is such tool exist without counting IDA PRO. And is there any GUI version of it if exist - because I really don't want to debugging with terminal. My OS X version is Snow Leopard. I want to disassemble and debug an PowerPC app which runs with Rosetta on OS X 10.6.
Haven't tried it myself but I've heard about otx (object tool extended):
otx stands for "object tool extended". It uses otool (object tool) to disassemble a Mach-O executable file, then enhances the disassembled output. Simple enhancements include adding the machine code of each instruction and the offset of each instruction from the beginning of a function. More complicated enhancements include displaying the names and data types of Objective-C methods even if symbols have been stripped, and adding comments that describe member variables, function calls, static data and more.