This PHP extension is a 1:1 wrapper for the FreeBSD libbe(3) library.
FreeBSD libbe(3) is a library for creating, destroying and modifying ZFS boot environments.
The official documentation for FreeBSD libbe(3) can be found here.
% git clone https://github.com/theonemcdonald/php-ext-libbe.git
% cd php-ext-libbe
% phpize
% ./configure
% make
$ make install