APCu is userland caching: APC stripped of opcode caching in preparation for the deployment of Zend Optimizer+ as the primary solution to opcode caching in future versions of PHP. APCu has a revised and simplified codebase, by the time the PECL release is available, every part of APCu being used will have received review and where necessary or appropriate, changes. Simplifying and documenting the API of APCu completely removes the barrier to maintenance and development of APCu in the future, and additionally allows us to make optimizations not possible previously because of APC's inherent complexity. APCu only supports userland caching (and dumping) of variables, providing an upgrade path for the future. When O+ takes over, many will be tempted to use 3rd party solutions to userland caching, possibly even distributed solutions; this would be a grave error. The tried and tested APC codebase provides far superior support for local storage of PHP variables. This package supports PHP 5.x. Use php-apcu if you are using PHP 7.x