An article in the Washington Post (it’s worth reading it) describes it like this:
“A globe-spanning U.N. digital library seeking to display and explain the relics of all human cultures has gone into operation on the Internet for the first time, serving up mankind’s accumulated knowledge in seven languages for students around the world.”
It’s obviously just beginning, but it looks pretty nifty. It’s worth it to read the “Help” section first. I quickly found a nice video of Ellis Island immigrants I’m going to use in my U.S. History class.