RUNOFF

RUNOFF was an early text formatting program, developed in the mid-1960s for the Compatible Time-Sharing System (CTSS) at the Massachusetts Institute of Technology. It is recognized as one of the first digital typography tools, enabling users to prepare documents for printing on line printers and daisy wheel printers. Its command-driven approach to document layout directly influenced the design of subsequent word processors and document preparation systems.

History and development

RUNOFF was created in 1964 by Jerome H. Saltzer, a computer scientist at the Massachusetts Institute of Technology. The program was written for the Compatible Time-Sharing System, an influential early time-sharing operating system developed at MIT. Its development was part of a broader effort, supported by the Advanced Research Projects Agency (ARPA), to enhance the utility of computer systems for non-numeric tasks like document preparation. The name "RUNOFF" is said to be a pun on the phrase "run off a copy," referring to the act of printing. The program's functionality was a significant advancement over earlier, more primitive text output methods, establishing foundational concepts for separating document content from formatting instructions.

Syntax and features

The language used a simple syntax where commands began with a period (`.`) at the start of a line, followed by a one- or two-letter command code. Common commands included `.pp` for paragraph, `.sp` for space, and `.fill` for text justification. It supported basic pagination, allowing users to define page headers and footers, and could handle indentation and line centering. The program processed plain text files, embedding these formatting directives within the document content itself. This "embedded command" model, while primitive by modern standards, introduced the core idea of a markup language, where specific character sequences control the presentation of the surrounding text.

Influence and legacy

RUNOFF's most direct descendant is the roff family of text formatters, which began with the 1970s Unix program `roff` and evolved into `nroff` and `troff` at Bell Labs. These tools became standard for technical documentation on the Unix operating system. The conceptual framework of RUNOFF also profoundly influenced later, more powerful systems like TeX, developed by Donald Knuth, and LaTeX. Furthermore, its model of embedded formatting commands can be seen in early word processor software such as WordStar and WordPerfect, which dominated the personal computer market in the 1980s. The program's legacy is evident in the persistent distinction between a document's source file and its final typeset form.

Example usage

A typical RUNOFF document would mix text with commands. For instance, to create a centered title followed by a paragraph, a user might write: `.ce` `A Sample Document` `.sp 2` `.pp` `This is an example of text processed by the RUNOFF program. The .pp command signals the start of a new paragraph.` When processed, this would produce output with the title centered, two blank lines inserted, and the paragraph text formatted with justified margins. This example illustrates the program's straightforward, line-oriented approach to controlling basic page layout elements, a significant capability at a time when most computer output was simple, unformatted listings.

Implementations and variants

Following its success on the Compatible Time-Sharing System, RUNOFF was ported to other early systems, including the Multics operating system. Its core ideas were reimplemented and extended in the DEC (Digital Equipment Corporation) community, leading to variants like the `RUNOFF` program for the TOPS-10 and TOPS-20 operating systems on PDP-10 computers. The most evolutionarily significant reimplementation was as `roff` for the Unix operating system on the PDP-7 and later the PDP-11, created by Joe Ossanna. This lineage split into the device-independent `troff` for phototypesetters and `nroff` for terminal and line printer output, which were later maintained and extended at Bell Labs and AT&T Corporation.