Windows only 
RocketDock is definitely one of my favorite application launchers because of how well it is designed to mimic the functionality of the Mac Dock. It can also be extended with skins to change the appearance, or with docklets to add more features.
The most popular addon across all of the different categories is the Stacks Docklet with over 800,000 downloads! As you can see in the screenshot to the right this emulates the Mac version of Stacks very well, and it’s pretty hard to tell it apart from the Mac Dock if you’ve got the right skin.
The addon hasn’t been updated in a little while, but that doesn’t mean development has stopped. In fact the developer is currently working on rewriting the Stacks Docklet, and if you’re feeling adventurous you can jump in on a pre-release version.
How does Rocket compare with ObjectDock Free? Is there a huge reason to change to Rocket?
@Michael Dobrofsky:
RocketDock is usb-portable.
Skins are cross-compatible.
RocketDock can load many ObjectDock docklets and vice-versa
(not OD’s web search or weather docklets, though).
***This Stacks docklet works fine for me in OD***
ObjectDock’s taskbar mimic is more robust:
With RocketDock, you can only “minimize programs to the dock”
(and it doesn’t always work as expected)
ObjectDock shows windows whether they’re minimized or not.
thanks Joe, I am going to check it out.
I wouldn’t say there is a huge difference between the two. Personally I’ve just always used RocketDock because they are normally pretty good about releasing updates. I don’t think you’ll notice much of a difference if you switch.
I use Rocketdock since a few years back and like it. This addon might be handy.