Heroku was founded in 2007 by Orion Henry, James Lindenbaum, and Adam Wiggins with a focus on hosting Ruby Rack projects. The company was acquired by Salesforce in 2011, and the Heroku platform is now part of Salesforce Platform. Heroku’s about page has a detailed timeline of major developments. It is considered one of the original Platform-as-a-service (PaaS) providers.
Heroku Postgres has been available as an add-on since 2010, and later as a standalone service. Redis has been supported since June 2015.