Troff is a document processing system developed by AT&T for the Unix operating system. A word processor (also more formally known as a document preparation system) is a computer application used for the production (including composition, editing, formatting, and possibly printing) of any sort of viewable or printed material. ... AT&T (formerly an abbreviation for American Telephone and Telegraph) Corporation (NYSE: T) is an American telecommunications company. ... Unix or UNIX is a computer operating system originally developed in the 1960s and 1970s by a group of AT&T Bell Labs employees including Ken Thompson, Dennis Ritchie, and Douglas McIlroy. ...

History

Troff can trace its origins back to a text formatting program called RUNOFF, written by Jerome H. Saltzer for MIT's CTSS operating system in the mid-1960s. (The name allegedly came from the phrase at the time, I'll run off a document.) A word processor (also more formally known as a document preparation system) is a computer application used for the production (including composition, editing, formatting, and possibly printing) of any sort of viewable or printed material. ... This article needs to be cleaned up to conform to a higher standard of quality. ... Run-off or runoff may refer to one of the following. ... Jerome H. Saltzer (born October 9, 1939 Nampa, Idaho) is a computer scientist who has made many notable contributions. ... The Massachusetts Institute of Technology, or MIT, is a research and educational institution located in the city of Cambridge, Massachusetts, USA. MIT is a world leader in science and technology, as well as in many other fields, including management, economics, linguistics, political science, and philosophy. ... This article is about the MIT Project MAC operating system. ... In computing, an operating system (OS) is the system software responsible for the direct control and management of hardware and basic system operations. ... The 1960s, or The Sixties, in its most obvious sense refers to the decade between 1960 and 1969, but the expression has taken on a wider meaning over the past twenty years. ...

Bob Morris ported it to the GE 635 architecture and called the program roff (an abbreviation of runoff). It was rewritten as rf for the PDP-7, and at the same time (1969), Doug McIlroy rewrote an extended and simplified version of roff in the BCPL programming language. The GE-600 series was a family mainframe computers of the 1960s, built by General Electric. ... The title given to this article is incorrect due to technical limitations. ... Rf or RF may stand for: Radio frequency, a term in broadcasting Right field(er), a defensive position in baseball Rutherfordium (Rf), symbol for the chemical element RF, rheumatoid factor RF, a Mazda piston engine The Russian Federation This is a disambiguation page — a navigational aid which lists other pages... DEC PDP-7 Minicomputer(circa 1965) A modified PDP-7 under restoration in Oslo, Norway The DEC PDP-7 is a minicomputer produced by Digital Equipment Corporation. ... 1969 was a common year starting on Wednesday (the link is to a full 1969 calendar). ... Portrait of Douglas McIlroy taken at the NATO conference in Garmisch 1968, courtesy of Brian Randell. ... BCPL (Basic Combined Programming Language) is a computer programming language that was designed by Martin Richards of the University of Cambridge in 1966; it was originally intended for use in writing compilers for other languages. ... A programming language or computer language is a standardized communication technique for expressing instructions to a computer. ...

The first version of Unix was developed on a PDP-7 which was sitting around Bell Labs. In 1971 the developers wanted to get a PDP-11 for further work on the operating system. In order to justify the cost for this system, they proposed that they would implement a document formatting system for the AT&T patents division. This first formatting program was a reimplementation of McIllroy's roff, written by Joe F. Ossanna. Unix or UNIX is a computer operating system originally developed in the 1960s and 1970s by a group of AT&T Bell Labs employees including Ken Thompson, Dennis Ritchie, and Douglas McIlroy. ... DEC PDP-7 Minicomputer(circa 1965) A modified PDP-7 under restoration in Oslo, Norway The DEC PDP-7 is a minicomputer produced by Digital Equipment Corporation. ... Bell Telephone Laboratories or Bell Labs was originally the research and development arm of the United States Bell System, and was the premier corporate facility of its type, developing a range of revolutionary technologies from telephone switches to specialized coverings for telephone cables, to the transistor. ... 1971 is a common year starting on Friday (click for link to calendar). ... Dennis Ritchie and Ken Thompson at a PDP-11 The PDP-11 was a 16-bit minicomputer sold by Digital Equipment Corp. ... Joseph F. Ossanna (December 10, 1928 - November 28, 1977), received his BSEE from Wayne State University, Detroit, Michigan, in 1952. ...

When they needed a more flexible language, a new version of roff called nroff (Newer 'roff' ) was written. It had a much more complicated syntax, but provided the basis for all future versions. When they got a Graphic Systems CAT Phototypesetter, Ossanna wrote a version of nroff that would drive it. It was dubbed troff, for typesetter 'roff', although many people have speculated that it actually means Times 'roff' because of the use of the Times Roman font family in troff by default. As such, the name troff is pronounced t-roff rather than trough. The title given to this article is incorrect due to technical limitations. ... Phototypesetting is a method of setting type with light (photo). ... Times Roman is a body text, serifed typeface. ... In typography, a typeface consists of a co-ordinated set of character designs. ...

With troff came nroff (they were actually almost the same program), which was for producing output for line printers and character terminals. It understood everything troff did, and ignored the commands which were not applicable (e.g. font changes). The Line printer is a form of high speed impact printer in which a line of type is printed at a time. ... A computer terminal is an electronic or electromechanical hardware device. ... In typography, a typeface consists of a co-ordinated set of character designs. ...

Unfortunately, Ossanna's troff was written in PDP-11 assembly language and produced output specifically for the CAT phototypesetter. He rewrote it in C, although it was now 7000 lines of uncommented code and still dependent on the CAT. As the CAT became less common, and was no longer supported by the manufacturer, the need to make it support other devices became a priority. However, before this could be done, Ossanna was killed in an auto accident. Dennis Ritchie and Ken Thompson at a PDP-11 The PDP-11 was a 16-bit minicomputer sold by Digital Equipment Corp. ... Assembly language or simply assembly is a human-readable notation for the machine language that a specific computer architecture uses. ... The C Programming Language, Brian Kernighan and Dennis Ritchie, the original edition that served for many years as an informal specification of the language The C programming language is a standardized imperative computer programming language developed in the early 1970s by Ken Thompson and Dennis Ritchie for use on the...

So, Brian Kernighan took on the task of rewriting troff. The newly rewritten version produced a device independent code which was very easy for postprocessors to read and translate to the appropriate printer codes. Also, this new version of troff (called ditroff for device independent troff) had several extensions, which included drawing functions. Brian Kernighan (pronounced Ker-ni-han; the g is silent; born 1942) is a computer scientist who worked at the Bell Labs and contributed to the design of the pioneering AWK and AMPL programming languages. ...

The troff collection of tools was eventually called Documenter's WorkBench (DWB), and was under continuous development in Bell Labs (renamed Unix System Laboratories, USL) through 1994. At that time, SoftQuad took over the maintenance, although Brian Kernighan continued to improve troff on his own. There are thus currently three variants of the original Bell Labs troff: DWB is an abbreviation for: Documenters WorkBench, a term used by the Unix System Laboratories for their troff family of computer program for document processing. ... 1994 was a common year starting on Saturday of the Gregorian calendar, and was designated the International year of the Family. ...

• An ancient variation from Bill Joy, still shipped by Sun.
• The SoftQuad DWB, based on USL DWB 2.0 from 1994
• The DWB 3.4 from Lucent Software Solutions (USL)

Use of troff and family was reduced somewhat in the 1990s, but it is still being used quite extensively. While Troff has been supplanted by other programs such as Interleaf, FrameMaker and LaTeX, it is still the default format of the UNIX documentation. William N. Joy (born 1954), commonly known as Bill Joy, co-founded Sun Microsystems in 1982 along with Vinod Khosla, Scott McNealy and Andy Bechtolsheim, and served as chief scientist at the company until 2003. ... Sun Microsystems is a computer, semiconductor and software manufacturer headquartered in Santa Clara, California, in Silicon Valley. ... In 1996, AT&T spun off its Systems and Technology units, along with the famous Bell Laboratories, to form a new company named Lucent Technologies (NYSE: LU). ... // Events and trends The 1990s are generally classified as having moved slightly away from the more conservative 1980s, but keeping the same mind-set. ... Founded in 1981, Interleaf was a company that produced a technical publishing software product with the same name. ... Adobe FrameMaker is a desktop publishing and Help authoring application published by Adobe Systems. ... The LaTeX logo, typeset with LaTeX LATEX is a document preparation system for the TeX typesetting program. ... Almost all substantial UNIX and Unix-like operating systems (*nix) have extensive documentation known as man pages (short for manual pages). The Unix command used to display them is man. ...

Features

Troff features commands to designate fonts, spacing, paragraphs, margins, footnotes and more. Extensions are available for producing tables, diagrams, and mathematics. Inputs to troff are plain text files that can be created by any text editor.

Extensive macro packages have been created for various document styles. A typical distribution of troff includes the me macros for formatting research papers, man macros for creating Unix man pages, and the ms macros for books, technical documentation, and reports. The troff typesetting system includes sets of commands called macros that are run before starting to process the document. ... Almost all substantial UNIX and Unix-like operating systems (*nix) have extensive documentation known as man pages (short for manual pages). The Unix command used to display them is man. ...

As troff developed, since there are several things which cannot be done easily in troff, work on several preprocessors began. These programs would transform certain parts of a document into troff input, making a very natural use of "pipes" in Unix -- sending the output of one program as the input to another (see pipes and filters). In software engineering, a pipeline consisting of chain of processes or other data processing entities, arranged so that the output of each element of the chain is the input of the of the next one. ...

The eqn preprocessor allowed mathematical formulae to be specified in a much simpler and more intuitive manner. tbl is a preprocessor for formatting tables. The refer preprocessor (and the similar program, bib) processes citations in a document according to a bibliographic database. Part of the troff suite of Unix document layout tools, eqn is a preprocessor that formats equations for printing. ... A preprocessor is a program that takes text and performs lexical conversions on it. ... Part of the troff suite of Unix document layout tools, tbl is a preprocessor that formats tables. ... Part of the troff suite of Unix document layout tools, refer is a preprocessor for dealing with citations. ... A bibliography is an overview of (almost) all publications in some category: works of some author publications about some specific subject publications published in some specific country publications published in some specific period publications mentioned in, or relevant to, a particular work (a bibliography of this type, sometimes called a...

Later, several new preprocessors appeared. The pic preprocessor provides a wide range of drawing functions. Likewise the ideal preprocessor did the same, although via a much different paradigm. The grap preprocessor took specifications for graphs, but, unlike other preprocessors, produced pic code. ... Since the late 1800s, the word paradigm has referred to a thought pattern in any scientific discipline or other epistemological context. ... ...

Reimplementations

groff is the GNU replacement for troff and nroff, and is free software. Groff is the GNU replacement for the troff and nroff text formatters. ... The GNU logo, drawn by Etienne Suvasa GNU is a recursive acronym for GNUs Not Unix. The GNU project was announced in 1983 by Richard Stallman with the goal of creating a complete UNIX-compatible operating system -- called the GNU system or simply GNU -- that is free software, meaning... It has been suggested that Free Software Replacements be merged into this article or section. ...

References

Mel Melchner letter explaining roff/troff/DWB history and status

External links

• The Text Processor for Typesetters
• The history of troff