PHP keeps on improving from release to release, as we have seen with PHP 5.6 then PHP 7. Amfphp has been updated to version 2.2.2 profiler to be compatible with the latest changes. PHP 5.6 is now fully supported. PHP 7 is still very fresh, so please try it in development environments but exercise caution if you want to try it in production.
Baguette AMF, the accelerator for Amfphp, now supports PHP 5.2 to 5.6. Work on supporting PHP 7 is ongoing.