This book constitutes the refereed proceedings of the 10th International IFIP WG 2.13 Conference on Open Source Systems, OSS 2014, held in San Jose, Costa Rica, in May 2014. The 16 revised full papers and 16 short papers presented together with 5 poster papers were carefully reviewed and selected from 61 submissions. They have been organized in the following topical sections: open source visualization and reporting; open source in business modeling; open source in mobile and web technologies; open source in education and research; development processes of open source products; testing and assurance of open source projects; and global impact on open source communities and development. The last section consists of five case studies and demonstrations of open source projects.