Eurisko stood for perhaps two decades as the most advanced AI ever created. And then Douglas Lenat abandoned it, decades ahead of the rest of us in the insight that recursive self-improvement is a mirage, there are no short cuts.

Douglas Lenat: "[..] so we can achieve Sergey [Brin]'s goal of a general AI by 2020"

Eurisko is a program written by Doug Lenat. It consists of heuristics, i.e. rules of thumb, including heuristics describing how to use and change its heuristics. It was applied to a number of domains with surprising success.