The Kindle Development Kit (KDK) is Java-based. From the FAQ:

What APIs are available to me in the KDK?

The KDK is comprised of two sets of APIs:

• Java version 1.4 Personal Basis Profile (PBP) APIs for mobile devices. PBP JavaDocs can be found at http://java.sun.com/javame/reference/apis/jsr217/.
• Kindle custom APIs which complement the PBP APIs and provide UI components, JSON and XML parsers, HTTP and HTTPS networking, secure storage, and other features. Other APIs like audio and dictionary access will be available in a future release of the KDK. KDK JavaDocs can be found at http://kdk-javadocs.s3.amazonaws.com/index.html.

All the information currently available to the public on the KDK is available at Amazon.

Unfortunately, that doesn t seem to include much detailed info on the KDK other than the development platform including emulator appears to be cross-platform (Windows, Linux & Mac). This could imply the use of Java, but is obviously pure speculation at this point. The Freescale processor and Linux-based kernel certainly could handle a Java runtime and the stated per application memory limits (100mb) would jibe with Java. Of course, a C/C++ SDK would be a bit leaner and also entirely possible.

The entire existing GUI for the Kindle runs on an embedded flavor of Java. So, I m pretty much assuming it s Java based. There may also be some security reasons (DRM, Whispernet abuse?) to confine people to a Java VM...

I really don t like this. Java is far from my first choice for embedded platforms. Why put a VM on a resource-limited device? Once, I played with an 8051 with a Java VM on it! Can you imagine?!? (I used the C route)

The one Java app I tried to port to the Kindle failed miserably because the embedded Java platform didn t support generics (which were used EVERYWHERE) or assertions (okay, not a big deal). Write once run anywhere? Riiight.

A huge number of platforms are running Linux, and it s dead easy to use Qt on just about any embedded Linux platform. I d say Qt is better at cross platform than Java at this point. I am somewhat biased, though. :)

The Kindle’s internal software is programmed in Java, so I expect the SDK to be Java-based. Amazon to Release Kindle SDK to Battle / Forestall Apple iSlate

It s a Java ME CDC device. And to that person that says Java shouldn t be used in small devices, it s currently used in several billion Java ME cellphones, Google Android phones, Blackberry phones, Blu-ray discs, smartcards, RFID tags, etc, etc.