Insight Into the Insight Toolkit

As a federally funded initiative, the Insight Toolkit (ITK) is intended to make a lasting software investment for biomedical image computing, enabling our communities with open-source algorithms for image segmentation and registration. Its 25-year success has been the result of a combination of carefully integrated factors: executive support, project management expertise, user involvement and skilled developers, the adoption of agile processes and tools, and maintaining clear business objectives in our execution. This history of ITK covers these factors, from the inception of the toolkit through its agile implementation and continuous testing and integration. The story includes motivations and fortunate enabling opportunities and ends with summary advice on how to succeed in creating a successful project of open-source software.