It is very important to understand the history of something to understand how it evolved to its current state. Over the years, the designers of Heroku have made several choices to make Heroku what we see it as today. Heroku has undergone many iterations of evolution. It all started when a few web engineers got together and built a platform as a service that looked very similar to the Unix platform. Developers could build their apps on Ruby and push them to the platform for hosting. All the value added services such as monitoring, logging, or databases were pluggable and easy to use. It was a web developer's dream come true.
The following is a short summary of Heroku's history that walks you through Heroku's evolution over the last several years:
Heroku was launched in 2007 by James Lindenbaum, Adam Wiggins, and Orion Henry.
Heroku was a Y-combinator start up and its base increased to over 2,000 apps and users in just the first six months.
Heroku started with addressing two common issues for web developers: deployment of applications and developer productivity.
By the end of 2007, Heroku came up with interesting features such as "instantly live" (deployment), "create and edit online" (online source code editing), and "share and collaborate" (code sharing).
Sometime later in 2008, Heroku was projected as a Rails-based web development framework and lot more focus was put on deployment and scaling of web applications.
Collaborative code sharing and development through Git paved way for increased interest in Heroku by the developer community. Soon a unified API was part of the Heroku offering.
During 2009, Heroku came up with Herokugarden—an application bed where the developer could create, deploy, and manage web applications. The API (Heroku commands) to manage web applications was part of this suite. This feature was phased out soon though.
Heroku also added the concept of "add-ons"—pieces of software (libraries) you could magically add to your web application and use almost on the fly. By the end of 2009, Heroku had almost 20,000 apps running on various platforms including mobiles.
Heroku was acquired by Salesforce in December 2010.
In the last few years, among others Heroku has done several important changes to the platform, including bringing in the new Celadon Cedar stack and supporting Java, Clojure, Python, Node.js, and Scala languages. It has also added an advanced support for the Postgres database.