High Quality Content by WIKIPEDIA articles! Most of the directories are very general in scope and list websites across a wide range of categories, regions and languages. But there are also some niche directories which focus on restricted regions, single languages, or specialist sectors. One type of niche directory with a large number of sites in existence, is the shopping directory for example. Shopping directories specialize in the listing of retail e-commerce sites. Examples of well known, general, web directories are Yahoo! Directory and the Open Directory Project is significant due to its extensive categorization and large number of listings and its free availability for use by other directories and search engines. However, a debate over the quality of directories and databases still continues, as search engines use ODP's content without real integration, and some experiment using clustering.

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