The Semantic Application Design Language (SADL) is both a controlled-English language for capturing semantic models, which are translated automatically to the Web Ontology Language (OWL), and an integrated development environment (IDE) that facilitates authoring knowledge bases in the SADL language. This documentation is for SADL Version 3. The Java source code for the SADL grammar and for the Eclipse-based IDE. SADL are Open Source under the Eclipse Public License. SADL documentation resides on SourceForge.net. The source code for SADL Version 3 resides on GitHub, Inc.