The Coral X-radiograph Densitometry System (CoralXDS) is a Windows-based program which provides a tool for measurement of linear extension, density, and calcification from coral X-radiographs. These quantities are determined for high-density, low-density, and annual bands. CoralXDS operates in two "modes": full mode and extension/luminance mode. Full mode measures linear extension, density, and calcification, while extension/luminance mode measures only linear extension. Extension/luminance mode requires only a coral image with scaling information. CoralXDS allows user specification of transect location and orientation on the coral image, and provides several options for automated and manual band selection. The output measurements are provided as plots and datasets.