RocketDock is not available for Linux but there are plenty of alternatives that runs on Linux with similar functionality. The best Linux alternative is Docky, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 50 alternatives to RocketDock and 12 are available for Linux so hopefully you can find a suitable replacement. Other interesting Linux alternatives to RocketDock are Cairo-Dock (Free, Open Source), Latte Dock (Free, Open Source), Plank (Free, Open Source) and tint2 (Free, Open Source).
BMPanel (bitmap panel) is a lightweight, NETWM compliant panel for X11 Window System, which contains a desktop switcher, taskbar, system tray and clock. The application is inspired by simplicity of fspanel. BMPanel has a modern look and feel, while keeping itself tiny and small.