The Sysinternals Troubleshooting Utilities have been rolled up into a single Suite of tools. This file contains the individual troubleshooting tools and help files. It does not contain non-troubleshooting tools like the BSOD Screen Saver or NotMyFault.
Source code of Sysinternals programs showed how to hide information in registry, hook and register API function for file system monitoring and other interesting stuff. The programs frequently used undocumented Native API functions to accomplish something impossible with standard WinAPI.