Official ConstantContact .NET SDK. It provides installation, documentation, and usage. To install, download and build the CTCTWrapper project. Next, place developers' credentials. To use, include namespaces, obtain an access token, create a service object, and use the SDK. Authored by Brian Vysocky.
Business Profiles, online database of business registration information, provides access to its massive database via the Business Profiles API. The database contains business registrations (e.g. corporations, limited liability companies, partnerships, etc.) and additional data on shareholders, directors, public filings, and more.