The One Laptop Per Child project suffered a blow this week, with Chief Technology Officer Mary Lou Jepsen quitting the nonprofit to start a for-profit company to commercialize technology she invented with OLPC.

Jepsen, who joined OLPC as its first employee in 2005 after Nicholas Negroponte started the effort, will pursue an opportunity to chase after "her next miracle in display technology," OLPC said in an e-mail sent on Sunday.

Jepsen was responsible for hardware and display development for the rugged and power-saving XO laptop, designed for use by children in developing countries. Though the laptop has struggled to find buyers, it has been praised for its innovative hardware features and environmentally friendly design.

Her last day with the organization is Dec. 31, though she will continue consulting with OLPC, according to the e-mail. Dec. 31 is also the end of OLPC's Give One Get One program, in which two XO laptops can be purchased for about $400, with a user getting one laptop and the other being donated.

Satisfied that XO laptops were shipping in volume, Jepsen noted in an e-mail that she was starting a for-profit company to commercialize some of the technologies she invented at OLPC.

"I will continue to give OLPC product at cost, while providing commercial entities products they would like at a profit," Jepsen wrote in an e-mail.

"I believe that the work I led in the design of the XO laptop is just the first step in changing computing," she wrote.

Powered by solar power, foot pedal or pull-string, the laptop doesn't rely on an electrical outlet to run, making it useful for situations where power is unreliable or unavailable. The laptop consumes between 2 watts to 8 watts of electricity from a specially designed lithium-ferro phosphate battery depending on usage, compared to 40 watts on commercial laptops depending on usage.

The laptop's battery lasts up to 21 hours because of custom-designed, efficient power-saving features implemented at the hardware and software level. Batteries in commercial laptops may explode at high temperatures, while XO's batteries can run and recharge in temperatures around 100 degrees Fahrenheit (38 degrees Celsius), Jepsen said in earlier interview.

OLPC is also designing a cow-powered generator that works by hooking cattle up to a system of belts and pulleys.

For connectivity, the laptop has mesh-networking features for Internet access.

Correction: This article was amended on January 2, 2008.