CSS Drop-Down Menu Framework is a free & cross-browser solution to create good looking menus.

Download package already contains examples but new themes can be created very easily.

Menus can be transformed by only changing the class name. Available transformations are:

• horizontal
• vertical left-to-right
• vertical right-to-left
• horizontal linear
• horizontal upwards.

The framework normally uses only CSS but for IE6, there is a JavaScript file that must be included.

Superfish is an advanced suckerfish menu plugin for jQuery.

It turns a standard CSS dropdown menu and tranforms it to a more powerful one (it gracefully degrades).

It supports both horizontal & vertical menus and unlimited sub-menus can be defined.

Considering the menu is generated from a CSS-dropdown menu, every sub can be easily styled too.

Other features of Superfish:

• Suckerfish-style hover support for IE6.
• Timed delay on mouseout.
• Animation of sub-menu reveal.
• Keyboard accessibility.
  
• Indicates the presence of sub-menus by automatically adding arrow images to relevant anchors.
• Drop shadows for capable browsers – degrades gracefully for Internet Explorer 6. Can disable shadows completely via options object.
• Can show the path to your current page while the menu is idle.
• Optional callback functions. The ‘this’ keyword within the handlers you attach will refer to the animated ul sub-menu.