Video: Google App Engine vs Heroku

Google App Engine lets you run web applications on Google's infrastructure. App Engine applications are easy to build, easy to maintain, and easy to scale as your traffic and data storage needs grow. With App Engine, there are no servers to maintain: You just upload your application, and it's ready to serve your users.
Heroku is the leading platform as a service in the world and supports Ruby, Java, Python, Scala, Clojure, and Node.js. Deploying an app is simple and easy. No special alternative tools needed, just a plain git push. Deployment is instant, whether your app is big or small.
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2017 - Google App Engine gets a firewall to keep up with Heroku

Google App Engine is finally getting a fully featured firewall. Until now, developers couldn’t easily restrict access to their applications on the service to only a small set of IP addresses or address ranges for testing, for example. Instead, they had to hard-code a similar solution into their applications and — because those requests would still hit their applications in some form — even those rejected requests would still incur costs. Now, they’ll be able to use the Google Cloud Console, App Engine Admin API or even the gcloud command-line tool to set up access restrictions that block or allow specific IP addresses. Because the firewall obviously sits in front of the application, rejected requests never touch the application and App Engine never needs to spin up an idle resource only to then reject the request. So now Google App Engine becomes more secure than Heroku.

2010 - Google partners with VMWare to adopt GAE for Enterprise to challenge Heroku

Google App Engine

In response to the recent launch of VMForce, Google today announced the upcoming version of its cloud platform for enterprise users - Google App Engine for Business. Until now, GAE was actually not suitable for hosting enterprise applications. First, GAE does not provides enterprise-ready support, security and service level guarantees. Besides, it supports only one database - Big Table, which is not used in existing business applications, and locks clients into one platform. The enterprise version of GAE, which is scheduled for 4 quarter of 2010, will fix these issues. Corporate customers will be offered a premium support, 99.9% SLA, administration panel for managing security policies. In addition, GAE will add support for SSL and SQL databases. Instead of difficult-to-forecast scheme of payment for computer resources, the clients will pay a flat rate - $8/month for app user.

Google VMWare

Like VMForce, Google App Engine for Business utilizes VMWare's technology. However, in this case Google and VMware partnership is less about them working together. Just Google added support for VMWare's Spring framework to its Google Web Toolkit. In result any Java-application developed on Spring can be quickly moved from in-house server to the GAE cloud. Besides, it can be quickly moved from GAE to another provider, that supports VMWare's vCloud (in particular, VMForce).

Google Apps Spring

In addition, thanks to Spring widgets, any Java-application on GAE can be easily adapted to any mobile device with a browser.

See also: Top 10 Cloud platforms for Enterprise