Description: API Monitor is a software that monitors and displays API calls made by applications. Its a powerful tool for seeing how Windows and other applications work or tracking down problems that you have in your own applications. The current version include Filters to monitor the following API Categories. Since API Monitor is a User-Mode application, it can only monitor API%60s called by User-Mode applications. API%60s called by drivers will not be monitored. NT Services cannot be monitored using this version of API monitor.