On Apr 19, 2003, some members had spotted referrals from eval.google.com/happier/quest/rateall.py followed by a question number and couple of different email addresses. You can read earlier threads here, [webmasterworld.com...] [webmasterworld.com...]
According to some [slashdot.org] sites [searchbistro.com],
It's one of the best kept secrets of Google. It's a mystery on Webmasterworld. Also in Europe (France) they don't know what to expect from that odd URL [eval.google.com....] Click it and you get ...nothing. The site reveals itself only if you have the proper login and if you use a network known by Google. Residues of Eval.google are found on the web, but the full content of the mystery site has never been published before. Here it is: the real story about Eval.Google. They use... humans!
The site claims it is some kind of the secret google evaluation lab!