Abstract: A method and system for transforming and manipulating program object code. A set of program object code is transformed into a form in which it may be readily manipulated, preferably a form which is independent of both the processor and the operating system with which the object code will execute. The transformed object code is manipulated, preferably to add error-checking instructions, but possibly to add other functions or to alter the functions of the object code. The manipulated code is then reverse-transformed to program object code of the same type as the original object code.