This comment in mongodb/mongo-php-driver#138 has received much praise for presenting an exhaustive list of Debian/Ubuntu packages for required/optional extension dependencies. We would do well to incorporate this list into the note on the following pages:

• http://php.net/manual/en/mongodb.installation.pecl.php
• http://php.net/manual/en/mongodb.installation.manual.php

Currently, these pages only suggest "libssl-dev" and "pkg-config". Moreover, we can remove the note about Homebrew on the manual installation page, since that is no longer relevant.