The document analyzes and compares the API features and developer programs of several electronic signature providers, including DocuSign, EchoSign, and RightSignature. It finds that the providers offer different API features for signing options, transaction verification, template support, document handling, forms, workflows, security, and data management. It also evaluates the providers' developer programs based on clarity, cost, community support, and finds they take varying approaches to engaging with developers. The document aims to provide insight into the capabilities and approaches of electronic signature APIs and their potential for integration.