Since Enlightenment is a Compositing Window Manager, you get those fancy drop shadows and window transparencies.

ENGADGET: How-to: Picking a Window Manager in Linux

Enlightenment, more specifically Enlightenment 16 or simply E16, is a Compositing Window Manager and is touted as "The original eye-candy window manager".

ENGADGET: How-to: Picking a Window Manager in Linux