This is a modification of the taxonomy_menu module which creates the menu from any number of single level vocabularies, which is useful in situations where each category shares the same subcategories. Take for instance a heirarchy like clothing. The levels might be as follows:
vocab 1: Autumn, Summer, Fall
vocab 2: men, women
vocab 3: shirts, pants, shoes
vocab 4: size 10, 12, 14
vocab 5: colour red, green yellow
In such a taxonomy there are men's and women's clothing in each of the Autumn, Summer and Fall categories. Within each gender there are shirts, pants, shoes and other clothing types. Then within each clothing type there are the same set of sizes and within each size the same set of colors.
To create this heirarchy as a fixed system using taxonomy would be tiresome and error prone. Instead the adv_taxonomy_menu enables you to set the the vocabulary to use at each level of the menu and creates the menu system from your directions. Furthermore you can create any number of such menus on the same site. It produces normal html code which can be themed using any standard css styling.
Note that this module can also be used for any single level vocabulary where you want to have a taxonomy menu. It has features which taxonomy_menu does not have such as a dynamic menu block and a views implementation.