Welcome to the SketchUp Software Development Kit. We appreciate your interest in interacting with the SketchUp and LayOut applications. The SDK contains the following items: SketchUp C API- This API is used to read and write information to and from SketchUp models. This can take the form of a SketchUp importer or exporter plugin, or a third party standalone application. SketchUp C API Documentation - Documentation for the SketchUp C API and the Importer/Exporter interface. It can be found here. LayOut C API- This API is used to read and write information to and from LayOut documents. This can take the form of a third party standalone application, or be incorporated into a SketchUp Ruby Extension. LayOut C API Documentation - Documentation for the LayOut C API can be found here. Sample C++ Projects - These projects demonstrate various uses of the SketchUp C API and LayOut C API. Migration Guide - Document explaining the steps required to migrate an existing SkpReader or SkpWriter plugin to the new SketchUp C API Importer/Exporter interface. It can be found here. Trimble SketchUp APIs Terms of Service - Document describing the terms of service for using the SketchUp SDK. It can be found here. This package contains the header files, binaries, reference documentation and examples you'll need to get started using the APIs.