"The uptake of AdBlock and its commercial sibling Adblock Plus has been gradual"

Adblock Plus is in no way a commercial offshoot of Adblock. I thought Adblock went defunct, Adblock Plus picked up where they left off (plus extra features), and then at a later point Adblock returned. Despite the name, it's not some industrial commercial version of Adblock. They're different plugins, with different people behind them..... right? ABP is open source, too (according to its site).

Adblock Plus is semi commercial, they sell whitelisting services to publishers (you can pay them to have your non-intrusive ads show by default).