DMOZ (short for directory.mozilla.org - it’s original domain name) is the open directory project – a human edited, hierarchical directory of links to sites on the World Wide Web. There is a huge human editing team splitting focus between finding and adding new sites to categories and ensuring the existing sections remain up to date and there are no dead links.
A listing in the Open Directory is extremely valuable for SEO purposes as they are not easy to come by and as a result give a significant advantage over competitors. The human editors will consider such factors as whether a site submitted for addition actually adds any further value to the section, carries too much advertising/commercial intent etc. As a result it can be extremely difficult to get a non-brand business listed on the site.
Whilst there have been a number of criticisms of the project (ranging from slowness and apparently inconsistent editing where some ‘friends’ of editors get their sites listed), Internet marketers would be wise to put those aside and consider it for the opportunities it presents. Overall it’s a good project offering real value to its users and to the Internet as a whole, albeit as Google’s domination of search has grown it’s usage is now significantly diminished.