Abstract: A method, apparatus, and article of manufacture for debugging target procedures contained in an object library or dynamic link library (DLL) on a running computer system. A "trace" DLL is created, wherein the trace DLL comprises a plurality of trace procedures. The trace procedures have a one-to-one correspondence with the target procedures contained in a target DLL. The trace DLL then acts as an interface between a software application and the target DLL. Rather than invoking the target procedure in the target DLL, the software application invokes the trace procedure contained in the trace DLL. In turn, the trace function in the trace DLL invokes the target procedure in the target DLL through an alternative entry point. The trace procedure may include debug statements, breakpoints, trace functions, printing functions, and other instructions that are executed before and after the call to the alternative entry point in the corresponding target procedure in the target DLL.