It's a very tiny freeware open source Windows desktop application. It can automatically shutdown your PC, when it finished some work, detecting constant low CPU usage.
If your CPU is under 10% for more than 10 seconds, it shuts down your PC. Very simple user interface! :)
Exporting 3452345 photos with Lightroom and going out? You can make sure your PC goes to sleep after it finished..
Windows Server 2008