What are some alternatives?
When comparing Heroku and Google App Engine, you can also consider the following products
Microsoft Azure - Windows Azure and SQL Azure enable you to build, host and scale applications in Microsoft datacenters.
Dokku - Docker powered mini-Heroku in around 100 lines of Bash
DigitalOcean - Simplifying cloud hosting. Deploy an SSD cloud server in 55 seconds.
OpenShift - OpenShift gives you all the tools you need to develop, host and scale your apps in the public or private cloud. Get started today.
Linode - We make it simple to develop, deploy, and scale cloud infrastructure at the best price-to-performance ratio in the market.
AWS Lambda - Lambda is a cloud service that Amazon Web Services (AWS) provides, which allows developers to run serverless code.