PHP Manual . ... History of PHP . History of PHP related projects . Books about PHP . ... One of the biggest strengths of PHP 3.0 was its strong extensibility features. ... The whole new language was released under a new name, that removed the implication of limited personal use that the PHP/FI 2.0 name held. ... PHP 4.0, based on this engine, and coupled with a wide range of additional new features, was officially released in May 2000, almost two years after its predecessor, PHP 3.0. ...