This document discusses how large open source projects can be monetized. It provides examples from the history of iText, an open-source PDF library. Early attempts like ads and donations generated little revenue. Selling documentation and support provided more income but were not scalable. iText adopted a dual licensing model, making the core open source under AGPLv3 but offering commercial licenses for proprietary use. This allows commercial use while preventing appropriation from large companies. Open core and business source models are also discussed as ways open source projects can generate sustainable revenue.