To fully exploit the business opportunity available through application programming interfaces (APIs), your designers must consider each API's purpose and audience as they answer a wide range of technical design questions. Although open Web APIs heavily favor REST messaging, the data shows that SOAP and messaging queuing can provide certain benefits, particularly for B2B APIs and internal APIs. As part of a series on API design practices, this report examines industry data and directions for positioning REST within your API strategy and for overall guidance on REST API design.