Hannu’s Blog

Open Sound System has been critizised because it’s not free, open sourced, GPLed or whatever. People claim it should not be called open because it’s in fact closed.

But what do “open” and “closed” mean after all?

During the early years of computing all software was written in assembly. There was no concept of operating system. Instead all applications (such as accounting software) accessed the hardware directly. The hardware had to be fully documented since otherwise nobody would not have been able to use it. In fact most (if not all) computer manufacturers shipped some software (in assembly language) with their hardware. So the situation was “all open” and also “all open source”.

Soon after that some new computer manufacturers entered the market. Since existing customers had already invested truckloads of money to their assembly software the new competitors had no other choice but to clone the original instruction set and hardware interface. The concept of “IBM compatibility” was born. Without compatibility it would have been too expensive for the old big customers to change their hardware vendor.

Few decades later the situation was different. Proper operating systems and programming languages had been invented. So 100% hardware compatibility was no longer necessary. It was possible to recompile the applications in some new system and get it running with reasonable cost. So being “open” was not the only choice.

Some systems even hidden all the hardware (even CPU instruction set) from the user and the software was implemented on top of some interpreted language (much like Java works today). The HP250 computer by Hewlett-Packard (see http://www.decodesystems.com/hp250.html) comes to my mind. It’s probably not the only or even the first system of this kind (I just have seen it). However all applications written for it were written on HP BusinessBasic. Nobody knew what kind of hardware architecture it had. A friend of mine managed to break behind the Basic interpreter and got a feeling that it was actually a 32 bit system (HP’s “bigger” HP3000 machines were still 16 bit systems during that time). However this was an example of “closed”.

In 80’s many (if not most) computers were “proprietary” and “closed”. They were running some operating system or BIOS that was not available for any other hardware. This was true with the first IBM PC too. IBM PC was MS-DOS based and Microsoft licenced DOS to some other computer manufacturers such as HP. However IBM’s BIOS was “proprietary”. During mid 80’s I used HP150 microcomputer that was also MS-DOS based. However it had it’s own (again “proprietary”) firmware that was called AGIOS (or something like that). Both HP150 and IBM PC were running the same MS-DOS which was character oriented. For this reason all applications had to use some firmware functionality to be able to do anything usefull such as graphics. So “IBM compatibility” got a new meaning. IBM compatible applications could be used only in IBM PC because they required services of the “proprietary” BIOS that IBM refused to license to anybody else. Fortunately Phoenix managed to reverse engineer the IBM BIOS and companies like Compaq and HP were able to produce their IBM compatible clones. Since that the PC was “open” again.

Then Windows was invented by Microsoft (btw, Windows 1.0 was originally shipped as a co-product of Microsoft mouse). Also Apple released the original Macintosh. Both products were “closed” again. MacOS was only available for Macintosh computers made by Apple. Windows was only available for MS-DOS. And so on…
Soon after that Unix started to gain more and more attention. It was considered “open” because AT&T licensed it to every computer manufacturer who wanted to license it. However every Unix vendor started to make their own extensions to it and soon the situation was approaching “closed” and “proprietary” again. Each vendor had their own windowing system running on top of X11 so GUI software written for one Unix variant was unusable under the others.

So several Unix manufacturers joined together in Open Software Foundation (OSF) and their developed the Motif GUI toolkit based on HP’s design. They even started to develop a common Unix version called OSF1 but after all only Digital used it in their Aplha machines (now it’s called Tru64Unix). Also Sun left outside OSF because they had developed yet anothe GUI toolkit that was incompatible with Motif (and better IMHO). And the story is getting too boring and I have to stop…

The “open” in Open Sound System comes from the above context. It means that the software is fully documented and any company can license it (or create their own implementation based on the specification). In fact this has happened in Linux and FreeBSD that both have their own implementations of the OSS API. In addition some companies like Sun and SCO have already licensed OSS for their operating systems.

This entry was posted on Monday, April 23rd, 2007 at 4:52 pm and is filed under Politics. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.