The Open Access Directory (OAD) is a wiki-based directory hosted by the School of Library and Information Science at Simmons College. The wiki is actually maintained, however, by an independent editorial board, with Nancy Pontika as editor (as of a March 24, 2016 announcement on the wiki’s home page).
Although it uses a wiki software, the OAD is (as its name suggests) first and foremost a directory, and most of its pages are lists related to OA in some way. These are useful to the reader looking to find additional resources like blogs, FAQs, and so on.
Some of the lists contain more commentary, such as the OA journal business models and OA book business models lists.
The directory does keep most of its pages updated, although the pages in the “lists under development” category on the home page are occasionally blank, and have been since their creation (occasionally as far back as 2014). Overall, though, the OAD is an excellent resource for people interested in OA.