SL4 is a mailing list on the topics of transhumanism and the singularity founded by Eliezer Yudkowsky founded around 2001.
It was named after the Alvin Toffler's Future Shock, in 1999 divided into Future Shock Levels by Yudkowsky.
In February 2009, Yudkowsky's posts were used as the seed material to create the community blog LessWrong, and Overcoming Bias became Hanson's personal blog. Today it is operated by MIRI.
- ↑ http://sl4.org/shocklevels.html