Conky is a lightweight system monitor that displays on your screen. Very useful if you want to know hd temps , cpu temps , download/upload speeds. There is a lot more than conky display aswell, more options than i can post here , but here are some screenshots of some conky screenshots. I would also recommend installing conky colors, which adds fonts etc to the standard conky which can be downloaded from here. Follow the instructions on that site. How to get conky to run on startup depends on which desktop enviroment you are using , but most allow users an easy way of doing this.