Christopher Langton (1948) is an American computer scientist and one of the founders of the field of artificial life. He coined the term in the late 1980s when he organized the first "Workshop on the Synthesis and Simulation of Living Systems" at the Los Alamos National Laboratory in 1987. Following his time at Los Alamos, Langton joined the Santa Fe Institute, to continue his research on artificial life. He left SFI in the late 1990s, and abandoned his work on artificial life, publishing no research since that time.
Langton's Ant Colonies - a two-dimensional universal Turing machine with a very simple set of rules but complex emergent behavior (1986)
Langton's Loops - a particular "species" of artificial life in a cellular automaton created in 1984 by Christopher Langton. They consist of a loop of cells containing genetic information, which flows continuously around the loop and out along an "arm" (or pseudopod), which will become the daughter loop.
Overview paper on Artificial Life by Langton from the 1990s: https://web.archive.org/web/20070311225322/http://www.probelog.com/texts/Langton_al.pdf
After Langton disappeared from the ALife community in the 1990s, he reappeared in the 2007 as author of "Military Balance" by "International Institute for Strategic Studies".