I have a Lubuntu install, and have noticed that the HUD that goes along with something called Unity does not appear when I tap alt. I learned about the HUD from the notes about the most recent Ubuntu patch, which I think was "Precise Pangolin".
That page has a small section about the HUD, but I couldn't find any links to talk about it more in depth. The patch notes indicated that it should have been installed automatically, and I was wondering if there are any known reasons it might not be working. I have looked through the existing questions and could not find a similar question.
My only thought were that I run Lubuntu, and that I have no idea what Unity is. Please advise.