Adblock Plus 1.8.5 is an app that interacts with Safari, while Adblock Plus 2.6.4 is a Firefox add-on...an entirely different animal, albeit with the same name (but a different developer), neither of which should be confused with AdBlock, the Safari extension.
Adblock Plus is an open source project created by Wladimir Palant in 2006. Eyeo was founded in 2011 by Wladimir Palant and Till Faida to make its development sustainable.
dkmarsh—member, FineTunedMac Co-op Board of Directors