The One Laptop Per Child (OLPC) Project is asking software coders to develop free, open-source educational computer games for the XO laptop, continuing its push toward a September launch date.

OLPC on Thursday offered a laptop prize for software teams who create new games during a three-day "game jam" scheduled to begin June 8 on the campus of Olin College, an engineering school in Needham, Massachusetts.

By increasing the software available for the XO, OLPC hopes to encourage governments of developing countries to order more laptops, pushing the group to its sales goal of 3 million units by May 30. OLPC had collected 2.5 million orders by late April, but needed to boost sales enough to order bulk computer parts and stick to the manufacturing schedule.

An OLPC spokesman was sanguine about the goal, calling the date an arbitrary deadline that could also be affected by software and hardware changes as developers put the finishing touches on the beta version of the XO laptop, according to an e-mail from OLPC's public relations agency.

However, production has already slipped from an original date in July, and could be set back further by spiraling prices. Last month, OLPC founder Nicholas Negroponte said the price of the "hundred-dollar laptop" had risen to $US175.

Negroponte also says that his nonprofit effort is being hurt by well-funded competition from Intel's Classmate PC, also a low-budget, power-efficient PC designed as an educational tool for children in developing countries.

The game-making contest marks a new effort by OLPC to increase momentum for the XO.

"The purpose of the game jam is getting people together to hack for a couple of days. Hopefully this will be the first of many," said SJ Klein, OLPC's director of content.

XO users already have their choice of certain games in a "Pygames" library of open-source applications written in the Python programming language, and the XO's eToys application that allows children to create their own basic media and games, he said.

But in the game jam, developers could create new types of games that rely on features of the XO's design such as mesh networking between nearby users, an integrated still or video camera, and a tablet mode for mobile gaming.

"There aren't too many games right now that take advantage of mesh style networking," said Klein, referring to the XO's ability to use Wi-Fi to communicate with other users up to a kilometer away, and display them as icons on its Sugar interface. "There are networked games, sure, but they aren't sensitive to the ability to display the presence of other users depending on where they are in relation to you, or to pop up on the screen when they are close enough."

Beyond creating games that teach specific tasks like counting or reading, OLPC hopes the contest will produce templates that allow kids to build their own games, according to OLPC's development guidelines.

In keeping with the group's decision to use an open-source Linux OS in the XO computer, OLPC will release all games created at the weekend-long event under the open-source GNU General Public License, and post them on the SourceForge site.