In the keynote, Zeev shares the evolution of PHP’s major versions, the behind-the-scenes story of how PHP 7 came to be and its key benefits and features.
Official migration Guide - Migrating from PHP 5.6.x to PHP 7.0.x
Despite the fact that PHP 7.0 is a new major version, efforts were put in to make migration as painless as possible. There are a few incompatibilities and new features that should be considered, and code should be tested before switching PHP versions in production environments. This official guide will help you to easily migrate from PHP 5.6 to PHP 7.Read more