This book constitutes the refereed proceedings of the 16th IFIP WG 2.13 International Conference on Open Source Systems, OSS 2020, held in Innopolis, Russia, in May 2020.* The 12 revised full papers and 8 short papers presented were carefully reviewed and selected from 42 submissions.

The Ecosystem of openKONSEQUENZ, a User-Led Open Source Foundation.- The development of data collectors in open-source system for energy efficiency assessment.- Challenges of Tracking and Documenting Open Source Dependencies in Products: A Case Study.- An Empirical Investigation of Sentiment Analysis of the Bug Tracking process in Libre Office Open Source Software.- Emotional Contagion in Open Software Collaborations.- An Open Source Solution for Smart Contract-based Parking.- Using open source libraries in the development of control systems based on machine vision.- An Empirical Analysis of the Maintainability Evolution of Open Source Systems.- Development of Cloud-based Microservices to Decision Support System.- Using of Open-source Technologies for the Design and Development of a Speech Processing System Based on Stemming Methods.- Combining Two Modelling Approaches: GQM and KAOS in an Open Source Project.- An XQuery Specification for Requests with Preferences on XML Databases.- TheStrategic Technical Debt ManagementModel: an Empirical Proposal.- How the Cathedral Embraced the Bazaar, and the Bazaar Became a Cathedral.- An open source environment for an agile development model.- InnoMetrics Dashboard: The design, and implementation of the Adaptable Dashboard for Energy-Efficient Applications using Open Source tools.- Using FLOSS for storing, processing and linking corpus data.- MegaM@Rt2 EU Project: Open Source Tools for Mega-Modelling at Runtime of CPSs.- .NET Runtime and Tools for Tizen Operating System.- Energy e cient software development process evaluation for MacOS Devices.