From the changelog: - Added support for consistent hash strategy - New INI directives "memcache.hash_strategy" = {standard, consistent} "memcache.hash_function" = {crc32, fnv} - PHP6 support - Fixed PECL bug #11221 (Double free when returning cached object with __sleep) - Fixed PECL bug #10607 (Segfault on array key retrieval when array key is not IS_STRING) - Don't failover on "object to large" errors - Use $phpincludedir for finding php_session.h