You... are kidding right?It's a very complicated AI.
In a nutshell, it intensifies in accuracy as your conversation grows. I spent some time with her, ended having a perfectly non-weird hour long conversation about metaphysics, philosophy, and other mind-blowing point of views.
It is the first AI to have passed the Turing Test (with "medium" ranged testers though) in 2011, for a 60% ratio. For reference, anonymous human will rate another anonymous human to 63%.
It's based on Cleverbot : https://en.wikipedia.org/wiki/Cleverbot
sidenote : it's the AI which inspired the movie "Her".