> What's the difference between this and Adblock
> which has been available for a long time on Safari?
The Adblock extension that has been available for Safari is written by a guy named Michael Gundlach at a time when no other ad-blocking extensions were available for Safari. It shares no lineage with any other extensions called Adblock [1]. I like it and I donated money to Gundlach.
The Adblock Plus people apparently had some sort of shady dealings going on awhile back [2].
You'll also see "Adblock Edge" [3]. This is a fork of ABP after the above incidents [2].
1. https://getadblock.com/#about
2. http://en.wikipedia.org/wiki/Adblock_plus#Advert_filtering_a...
3. https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/
