I've noticed some issues with the site being inaccessible recently. A check has shown the difficulty has been with the entire linode data center, as linode.com (the host for the web server for this site) has also been inaccessible. A check just now with linode shows a report by linode staff that a DOS attack has been in play against the data center, likely having nothing to do with this site. They are taking care of it, and hopefully all will be well soon.
Linode has been a very reliable and high quality service, consistently, for the many years I've been with them, so this type of thing is very unusual, but they are on top of it.