The original amscd package provides a CD environment that emulates the commutative diagram capabilities of AMS-TeX version 2.x. This means that only simple rectangular diagrams are supported, with no diagonal arrows or more exotic features. This enhancement package implements double, dashed, and bidirectional arrows (left-right and up-down), and color attributes for arrows and their annotations. The restriction to rectangular geometry remains. This nevertheless allows the drawing of a much broader class of commutative diagrams and alike.