PKG_

Apple Newton package
File type: Archive and compressed file
A pkg_ file extension is associated with the Apple Newton and other devices that use Newton OS. A pkg_ file contains data package.
What is pkg_ file?
File type category:
Archive and compressed file
Date updated: December 22, 2017
The pkg_ file extension is related with Apple Newton platform. The Newton platform was an early personal digital assistant hardware/software platform developed by Apple Computer (now Apple Inc.).
Development was started in 1989 and officially ended on February 27, 1998. Some electronic engineering and the manufacture of Apple's Newton devices was done in Japan by the Sharp Corporation.
Most Newton devices were based on the ARM 610 RISC processor and all featured handwriting recognition software. Most Newton devices were developed and marketed by Apple, but other companies, notably Sharp, Motorola, and Digital Ocean, also released devices that ran the Newton OS. None were as successful as Apple's devices.
PKG_ file extension was an uncommon file extension for Apple Newton package, common file extension was PKG and now Apple is using the PKG file extension for MAC OS X (macOS) installation packages.