uemacs

uEmacs is a text editor that runs in a terminal window. This repository is Linus Torvalds's fork of uEmacs/PK 4.0, which itself is an enhanced version of an older editor called MicroEMACS. The original MicroEMACS was written in the 1980s and uEmacs/PK added improvements while keeping the editor small and portable.

The editor is keyboard-driven and displays text across the full terminal screen. It was originally designed to run on a wide range of systems including various Unix flavors, MS-DOS, and VAX/VMS, though support for Amiga, Atari, and Mac was removed at some point. The feature set includes standard editing operations, a paragraph justification command, support for 8-bit ISO Latin characters, filename completion, and the ability to respond to terminal window resize events. A macro or scripting system is also present, based on variables and commands that can be configured through an initialization file.

The uEmacs/PK README notes it was maintained by Petri Kutvonen at the University of Helsinki, with Linus Torvalds credited as a contributor to bug fixes. The last official release from Kutvonen was version 4.0.15 in 1996. This GitHub repository is Torvalds's personal copy, which he continues to use and occasionally update for his own purposes, including as a writing tool when composing Linux kernel commit messages.

Building the editor on Unix requires copying the provided makefile template, adjusting it for the local system, and running make. The source is written in C and has no external dependencies beyond a standard C library and terminal support.