IgHook is a dynamic instrumentation library written by Lassi Tuura. It provides functionality to tap into any routine in an existing programme or library, and to maintain records: capturing stack traces, efficiently keeping track of which functions were called and how often, or keeping tabs on resources allocated and released to find leaks.

IgHook currently works on Linux (IA32 and, mostly, X86_64) and Mac OS X (PPC). It is used by IgProf profiling tools, but it is a general library and can be used for other application instrumentation purposes. In the past we have for example used it to provide a debugging utility to dump a stack trace whenever an exception is thrown in an application.