There are ART style and shadow style context menu for you to choose from. It supports multi-level and key navigation as well. Mif.Menu is released under the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License.
The animation needs to run when the user moves their mouse over and out of the navigation. The key thing to note is that any animation is stopped before attempting to animate again. This avoids animations queuing up from repeatedly moving the mouse in and out of the element.
Remember the time when I introduced Nice List of Open Source Fish Eye Menu. The dock fish-eye effect, whereby icons expand and contract as the mouse moves over them. Now, we have another solution for it, Mac Style Dock function allows this feature to be implemented easily.
Not only HTML is separated from CSS, but even CSS definitions are categorized into structural and thematic types. Thus creating a new drop-down means creating only a new theme since structure is permanent. What is more, creating a new theme is easy with available templates and takes 10-15 mins.
This is a versatile Ajax Tabs Content script that lets you display content pulled from external files inside a DIV and organized via CSS tabs. Features Inlcude: Fetch and display an external page, Supports auto mode, Ability to also expand/contract arbitrary DIVs, Ability to dynamically select a tab.