The Eclipse Foundation is home to some of the world’s most widely adopted open source projects, including Jakarta EE, Eclipse IDE, Eclipse Temurin, and many more. These technologies power critical infrastructure across industries. Often free of charge. But does “free” really mean cost-free? As projects like Eclipse Temurin approach milestones such as 600 million cumulative downloads, the disconnect becomes clear: while enterprise adoption is strong, financial support from those same users is often missing. This talk explores the reality behind the sustainability of open source and how the Eclipse Foundation supports its projects through a unique combination of revenue models, all while preserving vendor neutrality.. Key focus areas will include: Explaining the Eclipse Foundation's model: How the membership system and revenue-generating strategies, such as sponsorship, SWAG stores and targeted funding, are helping sustain the project. Understanding enterprise users: Who they are, their familiarity with the open-source ecosystem, and whether they want to support a foundation or simply pay for software. Highlighting the true costs: The infrastructure costs associated with a high-demand project like Temurin and raising awareness about the financial and operational savings enterprises enjoy by using it. By exploring the relationship between free-of-charge software and the real costs of its development and maintenance, this talk will show how users can give back and why doing so is vital to the project's long-term success.