Microsoft Research Detours - Detours is a software package for re-routing Win32 APIs underneath applications.
EasyHook - The reinvention of Windows API Hooking
WinAPIOverride - WinAPIOverride : This software allows you to monitor and/or modify any function of a process for any calling convention (stdcall or cdecl)
madCodeHook - "madCodeHook" offers everything you need to hook code (mostly APIs).
API Monitor - API Monitor is a software that monitors and displays API calls made by applications and services. Its a powerful tool for seeing how Windows and other applications work or tracking down problems that you have in your own applications
Deviare API Hook - Deviare is a professional open source hooking engine for instrumenting arbitrary Win32 functions, COM objects, and functions which symbols are located in program databases (PDBs).