It may be obvious that energy conservation and efficiency in software engineering will mean fewer shared resources are needed to keep our digital society running. Oft overlooked is that Free and Open-Source Software is well suited to achieve both!
Free and Open-Source Software guarantees user autonomy through the four freedoms. This autonomy permits users to install what they need and uninstall what they do not, bypassing bloatware and in turn conserving electricity. And this autonomy means users may choose to continue using older hardware but keep the software up-to-date, reducing global CO2 emissions by avoiding the unnecessary production and shipment of new devices. Moreover, Free and Open-Source Software guarantees transparency: this has always entailed that anyone may inspect and learn from how software runs; today, this transparency can be extended to include software’s energy consumption when in use. When energy demands are transparent, software can be made more efficient and users may make more informed choices.
Digital sustainability should be considered holistically: user autonomy and control over one's digital life as well as transparency in our digital infrastructure's resource consumption are a part of that. In this talk I will present how Free Software licenses enable users and their communities to directly influence the factors determining software sustainability.