Foreword: I've attempted to minimize the techno-jargon as much as possible in this blog to make it more readable, but note that there are still a few terms that may be confusing. Wikipedia or Webopedia are good sources if you need a better or more thorough definition. In previous years there have always been three major components to Diskeeper. One was the User Interfaces of which there are two – a graphical one (GUI), and a command line version (CLI). The second component was the defragmentation "engines" of which there were also more than one. A defrag engine was the executable that was responsible for consolidating file and free space fragments. It can in several forms, DfrgNTFS.exe, DfrgFAT.exe, DfrgNTFS1.exe (TVE and/or I-FAAST) were the "online" defragmentation engines. AutoNTFS.exe and AutoFAT.exe were the bootime defrag engines. You'll note that Windows names their built-in defragmenters similarly as that code was based off of technology we provided them in the mid-late 90's. The third piece is the Diskeeper Service (DKservice.exe.) which was responsible for scheduling defragmentation, handling the communication between the engines and the UI, as well as various other communication means (e.g. Check for Updates, Remote Control request from other computers, etc…)