First time "meeting" 'ACPu', I just wondered what it was before having to read the entire documentation...
This may(?) help: - https://www.google.com/search?q=what+is+APCu ;-)
APCu is APC stripped of opcode caching.
The first APCu codebase was versioned 4.0.0, it was forked from the head of the APC master branch at the time.
PHP 7 support is available as of APCu 5.0.0.
APCu can provide a compatibility mode, such that it can provide a drop in replacement for the applicable parts of APC.
First time "meeting" 'ACPu', I just wondered what it was before having to read the entire documentation...
This may(?) help: - https://www.google.com/search?q=what+is+APCu ;-)
Note that there are several cases when APCu cache does not persist and all set values are lost after PHP process exits. E.g. PHP CLI - successive CLI executions of the same script will find APCu cache empty.