http://mathoverflow.net/questions/57589/heuristic-behind-a-infty-algebras
See relevant nLab entries, also A-infinity space, A-infinity operad, A-infinity ring.
http://mathoverflow.net/questions/51817/question-about-a-infty-maps
arXiv:1205.6058 Homotopy unital A_infinity-algebras fra arXiv Front: math.AT av Volodymyr Lyubashenko It is well known that the differential graded operad of A_infinity-algebras is a cofibrant replacement (a dg-resolution) of the operad of associative differential graded algebras without units. In this article we find a cofibrant replacement of the operad of associative differential graded algebras with units. Algebras over it are called homotopy unital A_infinity-algebras. We prove that the operad bimodule of A_infinity-morphisms is a cofibrant replacement of the operad bimodule of morphisms of dg-algebras without units. Similarly we show that the operad bimodule of homotopy unital A_infinity-morphisms is a cofibrant replacement of the operad bimodule of morphisms of dg-algebras with units.
nLab page on A-infinity algebra