The file extension used to identify attachments sent using Newton OS email applications such as SimpleMail or EnRoute, as well as a Newton Connection data synchronization workfile. Each workfile has a set of associated backup files with the extension
# represents a number from 1 to 9.
nwt is also a command line application created by Eckhart Köppen that provides package management, data synchronization, and data export for a Newton device. This utility is part of the RDCL (Ruby Desktop Connection Library) framework.