This paper describes the work effort to update the “Organizational Project Management Maturity Model” (OPM3) and publish the second edition of the OPM3 organizational maturity standard. We provide a brief background on the field project management maturity models, and then focus on describing the details of the OPM3 2nd Edition update project, including insights on the project´s goals, how it was organized and how volunteers contributed. We provide feedback to the project management community on the update of a significant organizational maturity standard and note the challenges encountered during the work effort in a large and distributed project staffed by volunteers. Finally we discuss the lessons learned, and reflect on the experience as a whole.