VoxForge
VoxForge
Android is a new operating system for cell phones, designed by Google engineers. Unlike most existing cell phone operating systems,
it'll be friendly to applications created by outside software
developers.
Basically the phone (scheduled for 2008) will run on a Linux core, with Java-based apps.
Setup of the "early look" SDK is quite easy (if you know Eclipse). I was able to create the HelloAndroid app without much problem. When you press Run, the Android Emulator starts up, and you can see the results on the screen.
Here is what I have gleaned from comments from Dan Morrill on the Android Developer Google Group list:
From article: "Dalvik: how Google routed around Sun's IP-based licensing restrictions on Java ME". I'm paraphrasing here (see the article for details):
Sun released their "free java" source code under the GPLv2. For the Java standard edition there is an exception to the GPLv2 that makes it "reciprocal" only for the Java platform code itself but not for the user code running on it.
But there is no such exception for the mobile edition.
Google released Android, which contains the Dalvik virtual machine (just like Java's or .NET's). However, Android's programs are written in Java, which are compiled into regular Java bytecode (e.g. using javac), and then converted into Dalvik's bytecode (the "dx" tool does this by converting .class/.jar into .dex files). Therefore:
there is no need to ship a java virtual machine on your Android-powered phone and you can use your regular Java standard edition to develop your phone application ([which] means, you don't need to use Java ME anywhere at all).
Why is this last post important (re: "Dalvik: how Google routed around Sun's IP-based licensing restrictions on Java ME")?
Google is using GPL licensing for the core (i.e. Linux) of the Android telephony stack. However, for its apps it selected the Apache Software License. Therefore, developers can now develop Java telephony applications for Android using either open or closed/proprietary licensing.
Sun released Java under GPL. Sun also released phoneME under the GPL. phoneME is the open source version of their commercial mobile products. From their site:
phoneME Feature project is an open source development effort addressing the market and technical requirements of “feature phone” devices. The majority (about 80%) of mobile phones in the world today are feature phones. Devices of this type typically include a high-resolution screen, multiple forms of messaging (SMS, MMS, IM, Email), basic 2D and 3D gaming, a camera, music player, Internet browser, etc.
Powering all this functionality is a core set of Java ME technologies known as CLDC (the Java VM) and MIDP(the mobile information device profile). CLDC and MIDP are the most widely adopted Java ME application platforms used in mobile phones today. Layered on this base is a set of additional Java ME technologies often called “optional packages” that come in the form of JSRs (Java Specification Requests).
The phoneME Feature software includes the latest milestone & in-development implementations of CLDC and MIDP as well as implementations for a number of optional package JSRs.
Looks a lot like what Android is wants to do.
The question is, is Dalvik Google's approach to circumventing GPL of Sun's phoneME stack, or is it really about needing their own VM for performance reasons? Since Java ME is already used on many mobile phones, one begins to wonder if performance is really the issue.
Ken