Erhard Seminars Training (marketed as est, though often encountered as EST or Est) was an organization founded by Werner Erhard in 1971 that offered a two-weekend (60-hour) course known officially as "The est Standard Training". This seminar aimed "to transform one's ability to experience living so that the situations one had been trying to change or had been putting up with, clear up just in the process of life itself". An est site claims that it "brought to the forefront the ideas of transformation, personal responsibility, accountability, and possibility".
Background reading while watching episodes of The Americans.