While most of the work we do to keep HDC running, and improve it can be done without having to go offline. We find ourselves needing to make some changes that require just that. We have a maintenance window on June 18th, 8:00AM to 4:00PM Pacific time. HDC's Web interface will be completely inaccessible for the duration. If all goes well, we'll be back up and running in a much shorter period of time. Our API surface will still be operational, both in process and new submissions will continue to be evaluated during this time.
Look for follow on posts on the 18th announcing work start, and all clear.