VTK Origins

The enduring success of the Visualization Toolkit (VTK) has come as a surprise to the early developers of the system. Initially envisioned as a means to explore emerging technologies, and with a desire to collaborate widely with researchers and users in the visualization field, VTK is now over 30 years old, grown to a large-scale software system of more than five million lines of code, and supported by a large, active community. In retrospect, the reasons for this success go beyond technical capabilities, including the early adoption of a permissive open source license, accessible outreach through books and community engagement, sophisticated software practices, and the adoption of a hybrid business model to provide ongoing development. In this article, we speak to the origin story of VTK, include some behind-the-scenes stories, and identify factors contributing to its continuing success.