ORCID is an open, non-profit, community-driven effort to create and maintain a registry of unique researcher identifiers and a transparent method of linking research activities and outputs to these identifiers. The ORCID Registry is a repository of unique researcher identifiers which allows researchers to manage a record of their research activities. In addition, there are APIs that support system-to-system communication and authentication. ORCID makes its code available under an open source license, and will post an annual public data file under a CC0 waiver for free download.