The Founder and Co-Director of OpenCitations, Prof. David M. Shotton, peacefully passed away on Saturday, 18th May, after a long battle against illness. With his death, OpenCitations lost a Director, a Mentor, and a Guide. OpenCitations wouldn’t have existed without David’s foresight, which led him to design the first prototype of OpenCitations as a one-year project founded by JISC in 2010.