Zend Framework 3 depends on PHP 5.6+ and is optimized for PHP 7.

We recommend using either:

• Expressive, which is currently stable at version 2. If you have never developed with Zend Framework before, or not comfortable with zend-mvc, we recommend Expressive.
• Zend Framework version 3, via the Skeleton Application.

If you still not sure what to choose check our documentation: Should You Choose zend-expressive Over zend-mvc?

Development of Zend Framework 3 was highly focused on mitigating migration issues, and included a number of releases that provided forwards compatibility features to assist in migration. You can read about migration in our documentation.