This article describes the Cedar-14 stack, based on Ubuntu 14.04. What is a stack? Support period Cedar-14 is based on Ubuntu 14.04, which reached end-of-life on May 1st 2019. Learn more about Heroku’s stack update policy. Using Cedar-14 It is no longer possible to create new Cedar-14 apps, or to perform builds (code-deployments) on existing apps without first upgrading them to a newer stack. See