This includes pretty much everything.
Rushabh’s comment here can serve as a guideline for both speakers and reviewers.
Talks have to be informative and based on the work done by the speaker or expertise of the speaker the given talk. The talks should be about:
Introducing a FOSS project, or a new version of a popular project
Tutorial about using a FOSS project
Contributing to FOSS
Technology architecture
Engineering practice - tools,
productivity, debugging
Technology / FOSS licenses, policy
Story of a FOSS project / contributor
Speaker requirements:
FOSS contributor (OR)
Expert in the topic