(1) (newton) A unit of force in the MKS system. It is the force required to accelerate one kilogram by one meter per second squared.

(2) A set of mobile computing technologies from Apple introduced in 1993 with its MessagePad personal digital assistant (PDA). The ARM-based MessagePad included handwriting recognition, an infrared port for local data transfer and a fax/modem for e-mail and faxes. Although the MessagePad was the name of the device, it was more commonly called the "Newton."

The Newton eMate
In 1997, Apple offered the educational market a Newton-derived portable computer called the "eMate 300." Also using an ARM processor, the eMate had a full-size keyboard that was housed in a case similar in design to the iBook laptop, which was introduced two years later.

A Five-Year Reign
In 1998, Apple stopped production of Newton products due to competition from Palm PDAs, which were becoming very popular. Apple folded the Newton, Inc. subsidiary back into the company after having spun it off only a year earlier to specialize in the PDA niche. Some of the components of the Newton handwriting technology, which was often criticized for not being up to par in the MessagePad, made their way into the Mac OS X operating system a few years later. See PDA and ARM chips.