This is the genealogy of the programming language PostScript:

PostScript is a child of InterPress.
PostScript was first known as PostScript level 1 in year 1984.
It became PostScript level 2 in year 1994.
It became PostScript level 3 in year 1998, and has not changed much since that time.

Created by John Warnock and Chuck Geschke when they left Xerox to create Adobe and turn Warnock's InterPress into a commercial product.

This genealogy is brought to you by the Programming Languages Genealogy Project. Please send comments to thbz.

postmaster = P = pound on

PostScript n.

A Page Description Language (PDL), based on work originally done by John Gaffney at Evans and Sutherland in 1976, evolving through `JaM' (`John and Martin', Martin Newell) at XEROX PARC, and finally implemented in its current form by John Warnock et al. after he and Chuck Geschke founded Adobe Systems Incorporated in 1982. PostScript gets its leverage by using a full programming language, rather than a series of low-level escape sequences, to describe an image to be printed on a laser printer or other output device (in this it parallels EMACS, which exploited a similar insight about editing tasks). It is also noteworthy for implementing on-the fly rasterization, from Bezier curve descriptions, of high-quality fonts at low (e.g. 300 dpi) resolution (it was formerly believed that hand-tuned bitmap fonts were required for this task). Hackers consider PostScript to be among the most elegant hacks of all time, and the combination of technical merits and widespread availability has made PostScript the language of choice for graphical output.

--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.


And some time make the time to drive out west
Into County Clare, along the Flaggy Shore
In September or October, when the wind
And the light are working off each other
So that the ocean on one side is wild
With foam and glitter, and inland among stones
The surface of a slate-grey lake is lit
By the earthed lightning of a flock of swans,
Their feathers roughed and ruffling, white on white,
Their fully grown, headstrong-looking heads
Tucked or cresting or busy underwater.
Useless to think you'll park and capture it
More thoroughly. You are neither here nor there,
A hurry through which known and strange things pass
As big soft buffetings come at the car sideways
And find the heart unlatched and blow it open.

-Seamus Heaney

Perhaps its good to analyse the poetry you node. But this is a poem beyond words - about where our experiences outrun our powers to describe them. Poetry can speak for itself, should not always need to be dismantled and examined and tinkered with - and I want this one have its own way. As Robert Waller said "Analysis destroys wholes. Some things, magic things, are meant to stay whole. If you look at their pieces, they go away."

So I will not tell about in medias res and eye rhymes. But I can offer you some thoughts , I can offer my experiences of its setting - the west coast of Ireland. God what a beautiful place! So many feelings from the few short times I have been there. The irresistible freshness of the Atlantic breeze, the rugged timeless barren, untamed land. So many images demanding to be retold - coming down to Ballyferriter and the landscape curled up at the edges, unfolding like a map under a butter sun, the Three Sisters, heads high, looking west forever ... and coming round Slea Head on a bright and windy day, and seeing Dead Man asleep on a glittering sea... and cycling through the uplands of Donegal, past countless little mountain lakes, endlessly refilled by an unrelenting, wonderful drizzle...and walking home by starlight on a little island in West Cork, the sounds of conversation carrying two miles from the mainland over still and silent water...and sailing into the ruins of a deserted village in a little cove on a tiny island, defended by a pair of regal goats...and the stone tower in Liscannor half-deconstructed, starkly black in silhouette against an evening sky...and being discovered swimming naked by three fishermen on a beach in the back end of nowhere, leaving with a lobster for my trouble....and walking up a valley in the McGillicuddy Reeks, seemingly deserted, miles from anywhere, and havng tea with an old woman living alone at one end....

These are the places that rise up in my mind to greet Heaney's poem. For me. For you, maybe it's Nova Scotia, or Aomori or Oregon or your father, or something else entirely. You see, I can't tell you what it means - you have to tell me.

Number 69 on the list of 100 favourite irish poems

PostScript is a page description language. It is a powerful and full featured language (often likened to Forth) used to describe how a page should look in terms of lines, curves, fonts and text. A printer driver will write PostScript to describe how a page of output should appear, send this to a PostScript-enabled printer, which uses a PostScript interpreter to transform the PostScript into the image to be printed. Unlike other printer languages that use obscure escape sequences, PostScript is highly readable.

PostScript has its roots at the famous Xerox PARC, the research center in Palo Alto responsible for so many advances in computing. John Warnock and Martin Newell, two Xerox engineers at PARC, had created a language called JaM, for John and Martin. Later, it was refined into Interpress, PostScript's ancestor, that controlled Xerox laser printers. Warnock, and his boss, Chuck Geschke, attempted to get Xerox to commercialize the product. Xerox wasn't convinced the product had a future, so Warnock and Geschke left to form their own company, Adobe, in 1982. At first, they considered building a laser printer business, but eventually settled on creating a next-generation Interpress, and licensing it to printer manufacturers.

PostScript Level 1 was released in 1984. Adobe's big break came when Apple decided to incorporate PostScript into the Macintosh and LaserWriter printer. Linotype soon stepped in with PostScript enabled professional imagesetting equipment. The powerful combination of the Mac, PageMaker, and PostScript is said to have launched the desktop publishing revolution.

PostScript Level 2 was unveiled ten years later, in 1994. It added some minor refinements and fixed some long standing problems. In particular, the font handling was improved, including support for Asian languages, support for JPEG compressed images was added and the memory management was improved. Level 3, (or PostScript 3, as it is officially called), released in 1998, adds a few more refinements like PDF support and improved color separation.

In 1988, Adobe created a variant of Postscript specifically for computer displays, called Display Postscript. While Apple balked at this new technology that offered a unified imaging model for screen and printed output, Steve Jobs' new NeXT startup signed on. Display Postscript was just one of the many lauded features of the critically acclaimed but commercially ignored NeXT system. Another PostScript spin-off product is PDF, Adobe's highly successful Portable Document Format. PDF is, in essence, a stripped down version PostScript. Display Postscript lives on, as Display PDF, in the Quartz display technology in the NeXT-derived Mac OS X.

In addition to Adobe's PostScript, an open source PostScript interpreter called ghostscript is available. It will take any PostScript program as input and produce output for a wide array of output devices, and a more user friendly document browser, ghostview can display PostScript online.

The PostScript language itself is sort of a stack based postfix operator language, that looks a little like Forth, or LISP written backwards. A number in PostScript simply pushes itself onto the stack. Commands like moveto, pop their operands from the stack. Other commands like currentpoint push their results back onto the stack. For example, 10 20 moveto pushes the numbers 10 and 20 onto the stack; moveto pops 10 and 20 off and uses them as operands. See also PostScript Code to Draw A Sierpinski Triangle and PostScript command reference for more information on the PostScript language.

Post"script (?), n. [L. postscriptus, (assumed) p. p. of postscribere to write after; post after + scribere to write: cf. F. postscriptum. See Post-, and Scribe.]

A paragraph added to a letter after it is concluded and signed by the writer; an addition made to a book or composition after the main body of the work has been finished, containing something omitted, or something new occurring to the writer.

[Abbrev. P. S.]


© Webster 1913.

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