SimpleITK is a simplified, open-source interface to the Insight Segmentation and Registration Toolkit (ITK). The SimpleITK image analysis library is available in multiple programming languages including C++, Python, R, Java, C#, Lua, Ruby and Tcl. Binary distributions are available for all three major operating systems (Linux, macOS and Microsoft Windows). Software development is centered on GitHub using a fork and pull model. The project is built using the CMake tool, with nightly builds posted to the project's quality dashboard.