Commentary: Why we should hail IBM's Purple Book

IBM launched the PC industry by embracing openness 20 years ago, says AnchorDesk's Pat Houston. Now, what will Big Blue do for open-source Linux?

As they chronicle the computer age, let's hope the curators find a place in their archives for the Purple Book, a nondescript, plastic-covered binder that deserves preservation for its historical significance alone.

The Purple Book isn't just a relic, though. It's relevant to today--so much so that they just ought to include it in the computer science and business school curriculums.

What's the Purple Book? I only learned of its existence last week at the big bash celebrating the 20th birthday of the IBM PC. During a panel discussion that featured the founding fathers of the PC industry, including Bill Gates and Andy Grove, Lotus Notes creator Ray Ozzie began extolling the virtues of the technical reference manual IBM disclosed to everybody and anybody who wanted to know about the innards of its first PC.

The Purple Book "contained the hardware schematics for the IBM PC as well as the code listings for the ROM BIOS," Dave Bradley, one of the machine's 12 original designers, later explained to me. "It contained just about everything you'd want to know if you were going to build a device that would plug into the IBM PC."

In the Purple Book, as Bradley said during the panel, "We told all the PC secrets."

IBM wasn't the first personal computer maker to spill its guts. Apple published the source code for its Apple II. Atari and Commodore also offered similarly extensive documentations. But for Big Blue, a company that built a dynasty on proprietary products, the Purple Book represented a break with tradition as almost as radical as Martin Luther's breach with the Holy Mother Church.

Why did IBM so willingly bare the soul of its new machine? Bradley again: IBM wanted to "make it as simple as possible to design hardware and software that would work with the PC."

"We wanted the software and hardware industry to participate."

Participate they did. What's more, the Purple Book made the IBM PC easy to copy, and thus, in came the clones. The result: A de facto standard was born, and that standard made way for the widespread deployment and use of PCs. The rest, as they say, is history.

Was I the only one to savor, along with the salmon and filet mignon dinner they served that night, both the historical significance and the delicious irony raised by the Purple Book?

You tell me. Meanwhile, I'll explain.

The historical significance is the parallel that exists between the Purple Book of yesterday and the open-source movement of today. The comparison isn't a perfect one. The Purple Book did not constitute a license for use; IBM retained intellectual property rights.

Nevertheless, it's close enough for the Purple Book to serve as an important historical validation for the all-for-one-and-one-for-all approach to software development and the mandated sharing required by the open-source General Public License.

Another member of the panel that night, Dan Bricklin, the storied software developer who gave us the VisiCalc spreadsheet, agrees with me, at least in part. He says the Purple Book stands as "partial validation".

The reason: "It speaks to the importance of giving developers as much deep information as possible," he says. "The more information a developer has, the easier it is to get things to work properly, sooner, or most effectively. The more that's available to all developers, the better, especially if you think two guys in an attic or one kid in a dorm room may come up with the next big thing, like VisiCalc, Napster, or Dell."

Or Microsoft. And therein lies the delicious irony. The marquee name on this panel was Bill Gates, who probably programmed MS-DOS with his own personal copy of the Purple Book at his side. Thanks to IBM's unprecedented openness for the time, Bill Gates was on his way to becoming the world's richest man. Yet today his company is the most vocal critic of the open-source movement and the GPL.

While Microsoft has embraced a policy of sharing source code--with select customers--it's still a far cry from mimicking the IBM of 1981.

Just as IBM launched the PC industry by embracing openness 20 years ago, I wonder whether Big Blue will go into the history books as playing a similarly significant role today by taking a similar stance.

It has, after all, been unequivocal in its love for open-source Linux, to the point of devoting US$1 billion to the technology.

Why? Daniel Frye, the director of the IBM's Linux Technology Center, offered me several reasons. But one stands out: Some things--and an operating system is one of them--are just too fundamental to be locked up in a box. It's basic infrastructure, and basic infrastructure must be shared technology.

We know that, because we've seen the result--a result rooted in an historical precedent contained between the yellowing pages of a plastic-covered technical reference known as the Purple Book.