Heroku is one of the earliest PaaS platforms, founded in San Francisco in 2007 and acquired by Salesforce for $212 million in 2010. Known for git push deployment, autoscaling and a 150+ add-on ecosystem, it is a classic choice for rapid prototypes and small-team web app hosting.
Coolify is an open-source self-hosted PaaS from the Hungarian team coolLabs that deploys apps and databases with one click; 491,197+ self-hosted instances run 280+ one-click services.
CapRover is a free, self-hosted PaaS under the Apache 2.0 license, built on Docker and nginx, with about 10 minutes to first deployment and support for Node.js, Python, PHP, and more — ideal for developers who want to host their own apps.