This document outlines seven secrets of successful open source developers: 1) Passion - developers must truly enjoy coding open source projects, 2) Focus - on developing expertise in specific areas and solving real problems, 3) Persistence - open source development requires sustained hard work, 4) Mastery - developing strong programming skills through extensive practice and studying others' code, 5) Motivation - taking initiative and completing work, 6) Connections - finding mentors and collaborating effectively with others, 7) Luck - being prepared for opportunities and unexpected events. The document provides tips for open source developers such as choosing interesting projects, becoming active community members, presenting at conferences, and developing a variety of skills over many years.