Don't see that question very often. KDE stands for "K Desktop Environment", LXDE stands for "Lightweight X11 Desktop Environment", and Xfce originally stood for "XForms Common Environment". Xfce no longer uses the XForms toolkit, so they changed the acronym from XFCE to Xfce. Oh, and gnome stands for "GNU Networking Object Model Environment".
Mint 17.1 KDEHP Pavilion 17 Notebook, 8GB DDR3, 2.5GHZ A10-APU, Radeon HD 8650G