Scache is a different approach for PHP session data management. It provides a generic key-value data cache to use for transient session data storage. Scache also provides a shared keyspace, shared counters, and simple cache features. Scache's difference to other implementations is a tree-structured keyspace where one can easily operate only on required parts of stored session data and also invalidate groups of stored data by expiring whole subtrees. Despite its name, scache is not a cache. Scache stores all session data inserted until data is deliberately destroyed and so reduces the need to redundantly store the same data somewhere else. Scache consists of a daemon and a PHP extension.