 This paper surveys different cloud platforms suitable for a virtual online laboratory for operating systems courses. It concludes that private cloud and IaaS models are most appropriate for this purpose, and that customized cloud environments should be created instead of using pre-existing IaaS services from providers. Additionally, it reviews the author's previous research on virtualization tools and environments for operating systems, and cybersecurity operations courses, and compares four cloud platforms, Eucalyptus, OpenStack, CloudStack and OpenNebula. Based on their analysis, the authors select Eucalyptus and OpenStack as the best options for the virtual online laboratory. This article was authored by Alina Eselavnia and Vasyl Piolexiuk.