Official
https://en.wikipedia.org/wiki/Conky_(software)
https://github.com/brndnmtthws/conky
Screenshots
http://daviddavioblue.deviantart.com/art/haxOS-Conky-454353060
Use within KDE
If conky is properly installed, simply run conky and a default monitoring applet will appear in the background.
$ conky &