Gravitational COO, Taylor Wakefield, presents at the 2019 Open Core Summit, comparing Commercial Open Source Software ("COSS" aka, Open Core Software) to Proprietary SaaS. This presentation discusses why SaaS emerged, why COSS is now emerging and looks at the S-1 data of recently IPO'd companies in each cohort to validate the assumed benefits of each model. (Spoiler alert: each model can produce outstanding results.)