A quantity is a plain number at runtime; its unit lives in its type, so that a length in millimetres cannot be passed where one in pixels is wanted. The constructors make a number into a quantity.
The types of an edition. They are documented field by field, with the ontology terms each field maps to, in the format reference; they are listed here so that the signatures can link to them.
Digital editions of piano rolls: reading an edition and writing it out as JSON-LD, finding what it holds, changing it through operations on an immer draft, reading copies from scans and analysis files, collating them into versions, and working out what the edition can and cannot vouch for. The reproducing systems that play a version are entry points of their own, so that the emulator they need is loaded only where it is wanted.
The public interface of the library. Everything else under lib/ is its implementation and may change in any release: the in-place helpers the operations are built from, the date conversions of the serialisation, and the general utilities. So may the exports tagged
@internal, which the API reference leaves out.