Google Moderator (google.com)

I'm not sure you could create your own series two years ago.

It's surprisingly unheard of. For example, it hadn't been posted on HN before.

I was hoping the news was that the interface made any sense.

+1

The help screen explains a little more: http://www.google.com/support/moderator/

But it's still unclear to me how this differs from, say, a typical phpBB installation.

Ask a question, people submit potential answers, others vote those answers up or down.

To be fair, this thing was developed by a single guy for internal use. Someone then ported it to Google App Engine just to prove he could.

EDIT: Although I see it has evolved significantly along the way to its prestigious top-level URL.

They did. The guy who wrote moderator originally works on data center power management, so they recently hired somebody else to clean it up for public consumption.