Open Directory Project
The Open Directory Project (ODP), also known as dmoz, is an online directory that lists good web sites based on their subject. Web sites are listed in categories on this project. Each category is linked to relevant categories; the categories have a tree-like structure too.
Policies and procedures 
There are restrictions imposed on who can become an ODP editor. The primary gatekeeping mechanism is an editor application process wherein editor candidates demonstrate their editing abilities, disclose affiliations that might pose a conflict of interest and otherwise give a sense of how the applicant would likely mesh with the ODP culture and mission. A majority of applications are rejected but reapplying is allowed and sometimes encouraged. The same standards apply to editors of all categories and subcategories.