This volume constitutes the thoroughly refereed post-conference proceedings of the 9th
International Conference on Verified Software: Theories Tools and Experiments VSTTE 2017
held in Heidelberg Germany in July 2017. The 12 full papers presented were carefully revised
and selected from 20 submissions. The papers describe large-scale verification efforts that
involve collaboration theory unification tool integration and formalized domain knowledge as
well as novel experiments and case studies evaluating verification techniques and technologies.
