Google is bringing Android software development to the masses.
The company will offer a software tool, starting Monday, that is intended to make it easy for people to write applications for its Android smartphones.
The free software, called Google App Inventor for Android (http://appinventor.googlelabs.com/about/), has been under development for a year. User testing has been done mainly in schools with groups that included sixth graders, high school girls, nursing students and university undergraduates who are not computer science majors.
The thinking behind the initiative, Google said, is that as cellphones increasingly become the computers that people rely on most, users should be able to make applications themselves.
"The goal is to enable people to become creators, not just consumers, in this mobile world," said Harold Abelson, a computer scientist at the Massachusetts Institute of Technology, who is on sabbatical at Google and led the project.
The project is a further sign that Google is betting that its strategy of opening up its technology to all kinds of developers will eventually give it the upper hand in the smartphone software market. Its leading rival, Apple, takes a more tightly managed approach to application development for the iPhone, controlling the software and vetting the programs available.
"We could only have done this because Android's architecture is so open," Mr. Abelson said.
Mr. Abelson is a longtime proponent of making intellectual and scientific resources more open. He is a founding director of the Free Software Foundation, Public Knowledge and the Creative Commons, and he helped initiate M.I.T.'s OpenCourseWare program, which offers free online course materials used in teaching the university's classes.
The Google project, Mr. Abelson said, is intended to give users, especially young people, a simple tool to let them tinker with smartphone software, much as people have done with computers. Over the years, he noted, simplified programming tools like Basic, Logo and Scratch have opened the door to innovations of all kinds. Microsoft's first product, for example, was a version of Basic, pared down to run on personal computers.
The Google application tool for Android enables people to drag and drop blocks of code â€" shown as graphic images and representing different smartphone capabilitiesâ€" and put them together, similar to snapping together Lego blocks. The result is an application on that person's smartphone.
For example, one student made a program to inform a selected list of friends, with a short text message, where he was every 15 minutes. The program was created by putting three graphic code blocks together: one block showed the phone's location sensor, another showed a clock (which he set for 15-minute intervals), and third linked to a simple database on a Web site, listing the selected friends.
An onscreen button would turn on the program, Mr. Abelson explained, for perhaps a few hours on a Saturday night when the person wanted his friends to know where he was.
A student at the University of San Francisco, Mr. Abelson said, made a program that automatically replied to text messages, when he was driving. "Please don't send me text messages," it read. "I'm driving."
A program by a nursing student at Indiana University enabled a phone to send an emergency message or make a call, if someone fell. It used the phone's accelerometer to sense a fall. If the person did not get up in a short period or press an onscreen button, the program automatically texted or called the person designated to receive the alert.
"These aren't the slickest applications in the world," Mr. Abelson said. "But they are ones ordinary people can make, often in a matter of minutes."
The Google tool, of course, works only for phones running Android software. A sign-up with a Google Gmail account is required. The tool is Web-based except for a small software download that automatically syncs the programs created on a personal computer, connected to the application inventor Web site, with an Android smartphone. When making programs, the phone must be connected to a computer with a U.S.B. link.