Explore the benefits and strategies for contributing to Free and Open Source Software (FOSS) communities, with a focus on Java, in this 55-minute conference talk. Learn efficient learning techniques, network-building strategies, and the skills necessary to make valuable contributions to open source projects. Discover how participating in FOSS communities can benefit you, the community, and your employer. Gain insights from network science, neuroscience, education, and history to promote innovation and learning. Understand the who, what, where, when, why, and how of contributing to FOSS communities, with special emphasis on Java and the Japan Java User Group. Hear career success stories and lessons learned from the speaker's experiences interviewing and photographing thousands of developers. Get inspired to thrive in the fast-paced world of software development by leveraging the power of open source communities.