Disclaimer: I work at Docker.<p>The reason we are keeping the beta private is because we don&#x27;t believe the quality is good enough yet to &quot;open the floodgates&quot;. We are sending as many invites as the engineers are comfortable with - currently that&#x27;s several thousands per day. As we hit more and more edge cases (performance, stability, support for unusual configurations...) we are expanding the pool as fast as we can.