Google's now year-old App Engine infrastructure, previously limited to running only programs written in a particular species of Python, a less-than-mainstream tongue but an internal Google favorite, is learning to accept programs written in Java.

With the move, Google is reaching out to a broader base and interfacing with what it acknowledges are "businesses' existing technologies."

Apparently Google is using JVM 1.6 which means it should be able to support Ruby on Rails too.

App Engine's masters say Java was the first and most popular feature requested and that those requests extended to the other programming languages that have been implemented on top of the Java virtual machine along with the web frameworks and libraries.

It seems that marrying Java to Google's infrastructure is no mean feat. Google is currently testing the outcome. It can't guarantee that all the tons of Java code out there, particularly the stuff that ignores sandboxing, will work. It says, "We know that there will be some rough edges when it comes to compatibility."

To smooth those rough edges out, it's giving the first 10,000 interested developers a Java preview, looking for feedback.

The widgetry apparently wraps current App Engine APIs with Java standards like the Java Servlet API, JDO and JPA, javax.cache, and javax.mail. It also provides a secure sandbox that's flexible enough for developers to break abstractions at will.

The widgetry is supposed ensure easy deployment of Java code to all standard J2EE servlet containers including WebSphere and Tomcat.

Google says instead of using the underlying App Engine datastore APIs, developers can program against Java Data Objects or the Java Persistence API as a way to deal with App Engine's proprietary BigTable database.

Early support includes a Java runtime and integration with a new App Engine-friendly version of Google Web Toolkit 1.6 for turning Java into JavaScript and Google's Plugin for Eclipse.

Google says these tools provide a unified development experience for writing AJAX apps in a single language from client to server.

Meanwhile, as Google pours Java all over Apps Engine, it's also more quietly revving Python to make it faster under a project called Unladen Sparrow, a Monty Python reference.

According to a company blog - and having nothing to do with Java - App Engine has also added centrally managed access to on-premise corporate data and applications locked behind the company firewall complements of what's called Secure Data Connector (SDC), another serious play to put the enterprise in the clouds. It will work with Google Docs and Google Gadgets. The data is reportedly encrypted.

Oracle said its Siebel CRM apps will support SDC, opening the door to next-generation SaaS applications, multi-tenancy support and an "in-the-cloud Internet-based environment." It's also got an Oracle Gadget Wizard for Google Apps for its CRM.

There is also so-called Cron support for App Engine to automatically schedule tasks like report generation or DB cleanup at user-specified times and the ability to batch-import gobs of data from conventional databases into BigTable. Google hopes to provide matching export capabilities in the next month.

Google says in the year since App Eng was launched 150,000 developers have built 50,000 applications that now generate upwards of 100 million pageviews a day.