Xfce - Xfce is a lightweight desktop environment for UNIX-like operating systems. It aims to be fast and low on system resources, while still being visually appealing and user friendly.
RocketDock - RocketDock is a Mac OS X dock clone.
LXDE - Why will you like it? Less resource needs. You can use it on your less-pricey embedded board or salvaged computer. Component-based design. Don't want something in LXDE, or you don't want to use LXDE but only part of it?
ObjectDock - ObjectDock is the most popular animated dock for Windows.
KDE Plasma Desktop - Plasma Workspaces is the umbrella term for all graphical environments provided by KDE.
Cairo-Dock - Cairo-Dock / GLX-Dock 3. 4 is now available. Cairo-Dock 3. 4 is finally released! One year after the 3.