||QB stands for "Quick Binary." It's a PHP extension designed to enable faster handling of binary data. It takes a function written in PHP and translate it for a specialized virtual machine. The use of static type information leads significantly higher performance than under PHP's regular dynamic type system. A PHP+QB function can run anywhere from five to twenty times faster than regular PHP code. For even higher level of performance, one can compile PHP+QB functions to native code (on supported platforms).
QB performs code translation on a per-function basis. It does not affect in anyway code not specially marked. Interaction between PHP+QB functions and regular PHP code is basically seamless. A key design objective of QB is to let developers harness greater processing power than what baseline PHP offers without the risk involved in adopting a brand new platform.