Performance Improvements Nested calls Call stack pre-allocated by compiler Bundled opcode cache ✔ Generators ✔ Coroutines send('Foo'); $logger->send('Bar'); ]]> For an advanced explanation of coroutines, read this article by Nikita Popov Cooperative multitasking using coroutines ✔ finally ✔ list() in foreach ✔ Const array/string Dereferencing ✔ empty() support for functions/expressions ✔ curl upload functionality rewritten ✔ Simplified password hashing API php.net/migration55