  This article is a survey on the authors' proof of the isomorphism between
Heegaard Floer homology and embedded contact homology appeared in This article
is a survey on the authors' proof of the isomorphism between Heegaard Floer
homology and embedded contact homology appeared in arXiv:1208.1074,
arXiv:1208.1077 and arXiv:1208.1526.
