Chemical Markup Language

An XML-based markup language for representing chemical information including molecular structures, reactions, spectra, and other chemical data in a machine-readable format. CML encodes atoms, bonds, and molecular properties in a structured text format that can be processed by software, making it important for accessibility because it provides a semantic representation of molecular diagrams that can be rendered non-visually through speech, sound, or haptic interfaces. Unlike image-based molecular diagrams, CML-encoded structures allow assistive technologies to extract and present the underlying chemical relationships — atom types, bond orders, connectivity — enabling blind and visually impaired users to explore molecular structures programmatically rather than relying on visual pattern recognition.