Before ORCID was developed, some database providers developed approaches to author disambiguation. ResearcherID (developed by Thomas Reuters and used in Web of Science) and Scopus Author ID (developed by Elsevier and used in Scopus) are two examples of these efforts. Whereas ORCID is "a platform-agnostic identifier," ResearcherID and Scopus Author ID are connected to proprietary, subscription-based systems.
ResearcherID is a unique identifier to enable researchers to manage their publication lists, track citations and h-index, identify potential collaborators and avoid author misidentification. In addition, data associated with a ResearcherID can be exchanged with ORCID.
You can request a ResearcherID by visiting http://www.researcherid.com/ and providing your name, institution, role, and variants of your name that you have used.
If your publications are generally indexed by Web of Science, you might consider creating a ResearcherID account as well as an ORCID. It's easy to transfer information between the two profiles, including the list of publications from Web of Science. By having a ResearcherID, you can review variants of your author name to collect all of your publications together in Web of Science for inclusion in ORCID.
Scopus is a subscription-based, multidisciplinary database of peer-reviewed journal articles, books, conference publication, and other literature. Authors with publications indexed in Scopus are automatically assigned a Scopus Author ID. Users can search the lookup tool to locate an author's profile, which includes the identifier, references, citations of work, h-index, and subject areas.
Like ResearcherID, data associated with Scopus can be exchanged with ORCID.