Adblock Plus is by far the most popular adblocker available for the Firefox web browser. If you check stats on Mozilla's website you will notice that it has almost ten times the users as second placed NoScript Security Suite (21.4 million to 2.2 million).
Adblock Edge, a fork of Adblock Plus, works just like Adblock Plus in most regards but with the notable exception that it does not ship with an acceptable list of sites and advertisers.
The acceptable ads feature is enabled by default but can be disabled in the program preferences. The makers of the extension have been criticized for it ever since it was introduced by them as some companies pay for inclusion on the list.
While that is the case, their ads still have to adhere to the acceptable ads policy.
Adblock Edge was designed to do away with acceptable ads without sacrificing any other feature of Adblock Plus.
If you visit the Adblock Edge website on Mozilla right now, you will notice an announcement on it that the extension will be discontinued in June 2015.
You find the reason for the decision in the description:
Discontinued in favor of uBlock, a general purpose blocker, that not only outperforms Adblock Edge but is also available on other browsers and, of course, without "Acceptable Ads Whitelist".
It is unclear what discontinued means at this point in time as it is not explained on the page. The author could abandon the add-on or pull it from Mozilla's add-on repository.
It is unclear if the decision was at least partially impacted by Mozilla's decision to require add-ons to be signed.
The author of Adblock Edge recommends that users switch to uBlock, a popular up and coming adblocking extension that is not only available for Firefox but also other browsers such as Google Chrome.
The recommended extension is not without issues as well on the other hand. Gorhill, its creator recently left the project only to create a new fork of it. For Firefox users, it is easy enough however as there is only one uBlock extension available for the browser at the time of writing. Until that changes, it should be the one used by users of the web browser.
As far as Adblock Edge is concerned, it is unlikely that the discontinuation affects existing users of the extension immediately. In the long run however, it is recommended to switch to another add-on for the purpose as it won't receive updates anymore after June 2015.
Now You: Which adblocking extension are you using?