EZ is the default filename extension used for document files created by EZ Word word processor for Linux systems. EZ Word was the first program of its type available for Unix-based systems. EZ standard was developed at the Carnegie Mellon University in cooperation with IBM.

EZ Word is a component of Andrew User Interface System office productivity package. The solution was first presented on the pages od Linux Journal in 1994, but its development started in early 1982. Current stable version is designated 7.5.