• by Laurie Sullivan  @lauriesullivan, March 30, 2012

Google quietly set out to preview the Google App Engine that allows developers to build applications for use with cloud, mobile or Web services -- a launch that seems to prep for the sold-out Google I/O 2012 conference in June.

The App Engine allows developers to build applications on Google's infrastructure in Java or Python, Android or iOS, or HTML5, Chrome or Dart. The toolkit -- an effort to expand Google's app developer network -- comes with a local, downloadable software development kit, managed APIs, and a secure cloud runtime where developers can host the app. 

As of January 2012, Google's app strategy supports more than 100,000 developers, creating 300,000 apps -- mobile, social, consumer, business -- and 3 billion daily page views. Supporting the developers, the company released tutorials describing how to develop and deploy projects with Google App Engine. In an example project, a guest book demonstrates how to use the Python runtime environment and several App Engine services, including the datastore and the Google user service.

The company also launched Vault for Apps to support business customers. It preserves emails, chats and other correspondence required for regulation and compliance laws, and supports app developers through a dashboard in the event that it is required to search and find data for lawsuits. It costs $5 per user monthly.

Apps have become the new tool for a variety of services -- from ads to search to banking to music and games. Apple recently announced 25 billion app downloads from the Apple App Store, compared with a recent announcement from Google that its Android Market -- now Google Play -- supports about 1 billion monthly app downloads.

Google isn't the only company working to increase the proliferation of apps. All Facebook reports that Facebook is testing a revised version of its self-serve creation tool aimed at making it simple for marketers to optimize ads based on goals, whether installing apps or gaining likes.