This incident has been resolved.

The monitoring system came back online with the main website and management system. I'm going through the various auxiliary services next.

The NTP Pool management site and www.pool.ntp.org are back online.

The beta website at http://www.beta.grundclock.com/en/ is available again. With that working the production site should come back up shortly, too.

An internal switch in the main NTP Pool management and monitoring cluster has failed.

The NTP Pool system itself is up and running, but you can't add new servers and the existing servers aren't being properly monitored.