Please download S2Container-version.tgz and do "pear install".

% pear install /path/to/S2Container-version.tgz
install ok: channel://pear.php.net/S2Container-version

% pear list 
. . .
S2Container             version       state
. . .
%

By requiring "S2Container.php", S2Container.PHP will be available.

<?php
require_once('S2Container.php');
?>

Please carry out "pear uninstall", when you uninstall S2Container.PHP.

% pear uninstall S2Container
uninstall ok: channel://pear.php.net/S2Container-version

%