Founded in 2006, the B Lab, a nonprofit organization, created the certified B Corporations (B Corps). B Corps are businesses that satisfy a set of standards and benchmarks defined by social and environmental impact. B Corps and their supply chains are assessed on their policies and procedures around governance, workers, community, environment, and disclosures to the public. Certification means the company is a "purpose-driven" business that creates benefits for its stakeholders. By the end of 2018, over 2,700 companies across 60 countries and 150 industries have been certified as B Corps. This technical note discusses the founding of the B Lab and its certification process, including public disclosure; legal requirements and US state laws governing benefit corporations; and B Corp self-assessment. It explores benefits to B Corps and criticisms of the process as well as additional endeavors that resulted from the B Lab's collaborative efforts, including Global Impact Investing Network (GIIN), Impact Reporting and Investment Standards (IRIS), and Global Impact Investing Ratings System (GIIRS).