The limitations of backward compatibility and open architecture.

Petzold considers the problems of backward compatiblity:

Even before the introduction of the Macintosh, several companies had begun to create a graphical operating system for the IBM PC and compatibles. In one sense, the Apple developers had an easier job because they were designing the hardware and software together. The Macintosh system software had to support only one type of diskette drive, one type of video display, and two printers. Implementing a graphical operating system for the PC, however, required supporting many different pieces of hardware.

Moreover, although the IBM PC had been introduced just a few years earlier (in 1981), many people had grown accustomed to using their favorite MS-DOS applications and weren't ready to give them up. It was considered very important for a graphical operating system for the PC to run MS-DOS applications as well as applications designed expressly for the new operating system. (The Macintosh didn't run Apple II software primarily because it used a different microprocessor.)

(Petzold: pp. 371-372)

We're still dealing with this problem. Notice that both Linux and Windows have to support a vast array of hardware devices, which Apple doesn't have to worry about. When people talk about the smooth Apple experience, they are simply not comparing apples to apples —yeah, I know, bad pun. Additionally, in the case of Windows, the developers had to deal with backward compatibilty for MS-DOS apps until quite recently —was it Windows XP the first release that finally bropke away from it? Sure, that still doesn't change the reality that one product provides a better experience than the other, but it should definitely put things in perspective when what we discuss is the relative merits of the software developers involved in these projects.

Open architecture and open standards.

By now we all know about the importance of open standards in computing and how those companies that bet on it in the early 1980s ended up winning the war over the home computer. However, at the time the wisdom of betting on open standards was far from obvious.

If you were designing a new computer system that included a new type of bus, you could choose whether to publish (or otherwise make available) the specifications of the bus or to keep then secret.

If the specifications of a particular bus are made public, other manufacturers —so-call third party manufacturers— can design and sell expansion boards that work with that bus. The availability of these additional expansion boards makes the computer more useful and hence desirable. More sales of the computer create more of a market for more expansion boards. This phenomenon is the incentive for designers of most small computer systems that adhere to the principle of open architecture, which allows other manufacturers to create peripherals for the computer. Eventually, a bus might be considered an industry-wide standard. Standards have been an important part of the personal computer industry.

The most famous open architecture personal computer was the original IBM PC introduced in the fall of 1981. IBM published a Technical Reference manual for the PC that contained complete circuit diagrams of the entire computer, including all expansion boards that IBM manufactured for it. This manual was an essential tool that enabled many manufacturers to make their own expansion boards for the PC and, in fact, to create entire clones of the PC —computers that were nearly identical to IBM's and ran all the same software.

The descendants of that original IBM PC now account for about 90 percent of the market in the desktop computers. Although IBM itself has only a small share of this market, it could very well be that IBM's share is larger than if the original PC had a closed architecture with a proprietary design. The Apple Macintosh was originally designed with a closed architecture, and despite occasional flirtations with open architecture, that original decision possibly explains why the Macintosh currently accounts for less than 10 percent of the desktop market. (Keep in mind that whether a computer system is designed under the principle of open architecture or closed architecture doesn't affect the ability of other companies to write software that runs on the computer. Only the manufacturers of certain video games have restricted other companies from writing software for their systems.)

(Petzold: pp. 302-303)

Sure, we all know who was right. However, we also know that Apple has come back to life and become, once more, one of the most innovative companies in the business. Not only that, but few people would doubt that the main reason why they could afford this level of creativity is precisely because they control both the software and the hardware. It's part of the Apple experience that guarantees a smooth transition between products and a near-perfect compatibility between two different Apple devices.

Likewise, we also saw at the end of the 1990s the appearance of a new disruptive phenomenon: the open source movement. Where open standards applied mainly to hardware specs in the past —and Microsoft benefitted a lot from it—, Linux and other projects tried to spread the same philosophy now to the software world too. That's precisely why the moaning about the supposedly Communistic threat coming from the open source world that we hear from Microsoft's top execs from time to time is so self-serving. After all, they are the first ones who benefitted from IBM's decision not to play dirty and share the specs.

In any case, few people doubt that without these open standards the Internet wouldn't exist today and there is a good chance technology wouldn't play such a central role in our societies. It's precisely the adoption of open standards and protocols that made it possible for all this software craze to spread throughout the world in the 1990s.