How to create different top menu for different websites?

Question

In single magento installation we can create several websites. Is it possible to have different top menus for each of these websites?

Answer 1

When you create a website, you also create store group(s) and store view(s).

Each store group have its own catalog root, so your top menu can be different if you have set different root categories.

Furthermore, you can configure different design for your store views. So you can change the layouts and templates per views (or per website if you only have one store view and one store group).

Answer 2

Supplemental to Pilou's answer. In admin, you go to Catalog > Manage Categories and create new root categories that you can assign in System > Manage Stores.