  These notes are based on lectures given in Valencia in October 2008 and in
Stockholm in November 2008, in the framework of the Nordita workshop
"Geometrical aspects of String Theory". We introduce the notion of a metric
3-Lie algebra and review some of the classification results. We explain the
deconstruction of metric 3-Lie algebras in Lie algebraic terms and introduce a
general framework in which to describe other 3-algebras of relevance in the
description of three-dimensional superconformal Chern-Simons theories,
particularly those with N=6. The emphasis throughout is on the general ideas
and concrete examples.
