There are also a number of practical reasons it can take a while for a site to get listed in DMOZ:

The site is submitted to an incorrect category. Many sites are submitted to categories that are either too broad, too narrow, or unrelated to the content of the site being submitted. Most of the time, incorrectly submitted sites are sent to the appropriate category for review, but that will usually increase the amount of time that a site will ultimately wait for review. Submitting your site to the single most specific category relative to your site’s content will significantly improve your chances of getting your site reviewed.

The site is submitted to the wrong language section of the directory. For example, non-English sites are frequently submitted to the English-language section of the directory. As with sites submitted to the wrong category, editors have to redirect these sites to the correct language, which can increase the amount of time that they will await review.

The submitted site does not meet submission or editorial guidelines for inclusion. Quite often people submit sites that are incomplete, don’t contain enough content, or consist primarily of syndicated or mirrored content. Uniqueness of content is one of the most important factors editors consider when reviewing a site for inclusion.

The category has a backlog of submissions. This can result when the popularity of the topic, which may attract large numbers of both listable and unlistable sites, doesn’t match the interests of active or prospective editors. Submitting to one of these categories may mean a longer wait. (That doesn’t mean you should submit your site to the wrong category just because you think it doesn’t have a backlog – deliberately submitting your site to the wrong category is never a good choice.)

URBAN LEGENDS ( i.e. popular & fictional reasons ) as to why a site does not gain acceptance into ODP:

The category editor is corrupt and/or a competitor is keeping the site from being listed. DMOZ regularly receives allegations of corruption and abuse through its public abuse reporting system. Each report is thoroughly investigated and crosschecked. Most of these claims turn out to be baseless. In the rare case where there may be some truth to the allegation, the matter is dealt with immediately.

No one is monitoring the category. While a few categories in DMOZ may not have a listed editor that doesn’t mean there’s no one minding the store. All editors listed higher in a category’s hierarchy can and do edit subcategories. In addition, many editors have permissions to edit anywhere in the directory.

I’m certain there will be no shortage of comments to this post, but please consider the topics listed above and re-check your submission application again.

And if/when you do submit, please…please….please avoid any claims/jokes/sarcasm of offering money to get accepted into DMOZ. Editors apply zero sense of humor to these types of statements and it is a sure fire way to ensure your site does not gain entry. Ever.

Tips about submission to the DMOZ Index:

1. Don’t hype up your titles and descriptions on your submissions.

2. Be as descriptive as possible.

3. Select appropriate categories or you may find yourself rejected ~ TIP: Find your competition and you should be listed there. It might be tempting to be listed elsewhere, but this category is likely your best fit.

4. The directory lists alphabetically ~ You might be considering giving yourself a title to be at the head of the list, but you should always submit under your actual website name to avoid the risk of being rejected.

5. Do not submit duplicate sites (same site, different URL)

6. Do not submit URLs that redirect to another URL

7. Only submit once in a three week period. If you don’t hear anything, you can submit again or contact the category editor (you can find the editor at the bottom of the category you are submitting to).

8. You can also support the online community and volunteer to be an editor. There are a number of categories which need volunteers. You can find out more about being an editor at the DMOZ website.

Source : Bob Keating, Managing Editor, DMOZ Staff