This tool can be used to monitor and manage processes and modules. It is much more advanced than Windows Taskmanager. Works on all versions of Windows according to website.
Nuclear Processor has proven to be useful to determine what DLL's are loaded by a certain application. This can be very valuable when analysing application behaviour.
Warning: tool is hosted on a hacker-site. Tested and found to be virus free (according to McAfee). Tested on XP, works like a charm.