They're just named that way because Vista is the minimum supported operating system for those specific hooks. (XP uses different hooks). The "Vista" hooks work on Vista and up

I agree, I don't like seeing "Vista" anywhere either. I'll change our build process so it produces different filenames for these hooks.

@Mathieu: You should have the main DisplayFusion, then depending on your platform you'll have 1 or 2 hook processes as well. For performance reasons there hook processes need to run outside of the DisplayFusion main process. If you have any DisplayFusion windows open (like the Settings or Wallpaper windows) you'll see a 4th process. I hope this answers your question.

The background service handles a few things that require elevation, so it's required. You need 2 hook processes because each process can only hook processes that are the same bitness as itself. We care about performance as much as you, we optimize all of our code as much as we can. Everything that DisplayFusion is running needs to be running in order to function.