DMOZ (also called the Open Directory Project) is a very old "heirarchical" directory that uses volunteer editors who maintain their categories. "Heirarchical" means it has categories, subcatetories, and sub-sub-categories that can go down a dozen levels. It may be the last of the old directories from the 1990's, since Yahoo shut down the Yahoo! directory. The link above to DMOZ takes you to the Wikipedia article about DMOZ, which gives some of its long, involved history and mentions some of the controversies that have plagued DMOZ. Those include favoritism, category editors who block competitive websites, and various forms of personal bias on the part of editors.
Even in 2018, we still feel it is well worth the time and effort it can take to get into this directory. DMOZ is the directory used by AOL and many other places. Even Google used it at one point. It is a good directory to work to be listed in. Google appears to crawl through DMOZ and a link from DMOZ to your site helps establish your website's credibility.
Having a site that includes good content and is not blatantly attempting to sell without being informative is also key to being listed in the ODP. Make sure nothing is under construction or otherwise unfit for public consumption.
The title of the site as submitted to ODP should match the actual title of your website, within the <title>This is a title</title> tag in the code on the home page of your website.
Do make sure that your description contains keywords used within a complete sentence that makes sense, is typographically correct and accurately describes what people will find on your site. Don't use any promotional or competitive adjectives like "best", "cheapest" or "world's largest". Make sure your description will obviously still apply in a year or two. Describe it without using terms like "we", "they", "us", "I", and without stuffing in lots of keywords.
When submitting, give a real email address so the editor can tell you if you're disapproved and why. Don't worry, the editor won't send you any unsolicited email. Then after submitting, be patient. Editors respond at their own pace, but if you haven't heard back in six weeks, try politely nudging the editor of your category by email. If that doesn't work, nudge the editor of the next category up, or try submitting to a different category. Or simply wait. Some editors are on top of their categories; others have backlogs measured in years required to handle them. Be prepared to be very patient.
Here's that DMOZ says about how to submit your site to DMOZ.
Here's some advice about how to get into Netscape's Open Directory Project from one of the guides at the Open Directory Project, Beth:
From: Beth [email@example.com]
I'm an editor for the OPD. We don't always check our categories every day.
Wait 2 or 3 weeks after you've made the submission and check it. If it's not there, you can write an email to the editor of that category. The key is to be courteous and ask if they will be adding it soon. A polite reminder may get them to run over and add you.
Also, be sure you wrote a good description. A list of keywords won't work and they may leave your application in the unreviewed site section until they get around to writing a new one for you. This is a double edged sword as they may not write a description that is good for you.
If you write a short, objective, well thought out description that includes your keywords in sentence form, then it should be just a matter of the editor clicking on one button to get you added.