It's designed to allow uses to build apps by dragging and dropping visual blocks of code. The blocks editor uses the Open Blocks Java library. Open Blocks visual programming is closely related to the Scratch programming language, which was developed by the Massachusetts Institute of Technology (MIT) Media Laboratory's Lifelong Kindergarten Group.
The Java-based Kawa Language Framework, which is designed to implement high-level and dynamic languages and compile them into Java byte code, translates the visual blocks for the Android OS. An implementation of the Scheme programming language, it was developed by Per Bothner and distributed as part of the Gnu Operating System by the Free Software Foundation.
The educational perspective that motivates App Inventor holds that programming can be a vehicle for engaging powerful ideas through active learning. As such, it is part of an ongoing movement in computers and education that began with the work of Seymour Papert and the MIT Logo Group in the 1960s.
According to the Google blog, App Inventor "makes it easy for anyone -- programmers and non-programmers, professionals and students -- to create mobile applications for Android-powered devices."
But the amateurs seem to be the main target. Google talks about the potential user of the tool this way: "To use App Inventor, you do not need to be a developer. App Inventor requires NO programming knowledge. This is because instead of writing code, you visually design the way the app looks and use blocks to specify the app's behavior."
Harold Abelson, a computer scientist at MIT, took a sabbatical to lead the Google project, which has been under development for about a year. He told the New York Times , "The goal is to enable people to become creators, not just consumers, in this mobile world," adding, ""We could only have done this because Android's architecture is so open."
Underscoring Google's aim to make the drag-and-drop tool dead simple, Abelson and his team have been testing it primarily with sixth-graders, high school students, nursing students and university undergraduates, none of whom had coding expertise.
The free IDE is currently in beta, so glitches are to be expected, Google warns. Among the chief initial complaints: Users are reporting problems installing the software on machines running the 64-bit version of the Windows 7 OS. Google says it's looking into the problem.
Google has established a forum for users of the new IDE . You can register and download the IDE now on the App Inventor Beta site.
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