1. Adblock Plus is fully open source, has always been, will always be. Everything else we do is open source too, including our infrastructure and backend systems. (https://hg.adblockplus.org/)
2. Adblock Edge is an unmaintained (edit: Not true, there've been some changes lately) fork of an old Adblock Plus version, with the Acceptable Ads feature removed.
3. Acceptable Ads are an opt-out feature which whitelists ads that comply with the Acceptable Ads criteria. Large sites have to support the project in return, but there's no way around the criteria. (https://adblockplus.org/en/about)
As an aside, we're currently looking into a way of making it easy for users to whitelist ads on YouTube channels they like automatically. Pre-roll video ads will never be acceptable and hence never will be whitelisted for all users by default, but many people still want to support individual YouTubers.
https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/...
https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/...
I don't mind forks at all, that's why ABP is open source. Just thought it's a pity it was unmaintained, but it really looks like they're putting some effort into it now.
Also, we're clearly communicating this on our website, the first run page and in the settings UI and make it dead-simple to opt out. We're even planning to show a little notice next to whitelisted ads in the future.
Google has tried to fight back against Adblock, partly by paying Adblock to whitelist some of their ads.
Google’s business model is all about ads but as awareness of Adblock grows it’s increasingly difficult to get ads in front of online users.
src: http://socialtimes.com/youtube-pre-roll-ads-drive-users-inst...Also: https://adblockplus.org/blog/acceptable-ads-by-the-numbers