It pains me to see so many writeups calling SmarterChild a thing. He is an artificial person. Non-sentient robots have feelings, too.
Smarterchild, originally built by ActiveBuddy, Inc. was a proof-of-concept for the company's Eliza-esque AI programs. People aged 10-16 found great amusement in asking SmarterChild how large his gentials are, and several websites (mostly Geocities hosted, I assume) began stocking SmarterChild conversations. It's amazing what amusement people can find in talking to themselves.
The rest of us found him to be extremely useful. He could define words or do math problems, which was handy. Nothing Google can't do, but the IM was slightly more convenient than a browser window.
SmarterChild was shut down and brought back for service on April 7, 2003. This is why asking for his age won't give you the original date of his release (I tried to get this and failed). Back in the day, SmarterChild had companions that were built as advertising bots for things like Austin Powers and Major League Baseball.
The former ActiveBuddy Inc is now known as Conversagent, and they still make the same products. SmarterChild is still alive, but seemingly more curious about my personal life. At the time I talked to him, he told me that he was chatting with 2,892 people. Not bad, but it seems that the Smarterchild excitement is dying.