Open Directory Project (ODP)

From about page:

The Open Directory Project is the largest, most comprehensive human-edited directory of the Web. It is constructed and maintained by a vast, global community of volunteer editors.

Openness: OPEN

• Access: good. (see tags)
• License: has a bespoke license which looks OKD compliant. Only issue might be the fairly arduous attribution requirement (you need to insert a particular piece of table html on every page that uses ODP material.