Starshine: Operating Systems: Some Comments Some Comments on Computer Operating Systems

There are lots of computer operating systems. To the vast majority of computer users this is both unknown and uninteresting. Despite this many people will vehemently argue that the OS that they happen to use is superior to all others.

Often the OS seems to be simply an extension of the hardware platform on which it is run. Throughout the history of computer technology (from the mainframes through the mini's and throughout the "microcomputer" and "workstation" eras) hardware vendors have made attempts to lock their customers into particular software niches. This is hardly surprising, software is a far more lucrative proposition than hardware -- with much higher returns on very small capital investments.

However this advantage is weighed against the need for applications. Without a sufficient variety of applications a hardware platform cannot attract customers, which -- in a perverse and vicious cycle -- discourages developers from adopting a platform.

So, many hardware companies offer multiple operating systems. Commonly they have their own proprietary OS and some flavor of Unix or some microkernel OS with a set of Unix API's and "personalities."

In the documentation for C-Kermit -- the communications package from Columbia University -- they list about 800 supported operating systems. Of those they claim that almost 700 are Unix-like.

Currently my personal favorite is Linux. I'm also fond of other forms of Unix, including the 386BSD family: FreeBSD, NetBSD, and OpenBSD.

The best link pages I've found for reading about operating systems:

• Fari's Review of Operating Systems
• Sven's Operating Systems on the Web
• Patrick Bridges' Operating Systems Projects

Some sections on Yahoo! that cover this (and will hopefully have new and more up-to-date links than I'm likely to maintain):

• Yahoo! - Computers and Internet:Operating Systems
• Yahoo! - Computers and Internet:Operating Systems:Unix
• Yahoo! - Computers and Internet:Operating Systems:Research

There are some operating systems that are more obscure than others. For example KeyKOS uses a different security model than most of us are accustomed to. This is called a "capabilities system" (which I guess was first used in the Hydra operating system and to a lesser degree in Multics) To learn more about KeyKOS you might want to peruse its documentation.

(the only web reference I could find to the Hydra OS was in Comparison of MK++ with other OO Systems)

Mr. Shapiro e-mailed me to note that this project is still active (though I hadn't seen any changed to the web site in some time -- and have never seen any activity on the announce list to which I had subscribed).

Lucent Technologies' Inferno (which apparently grew out of the research they did on Plan 9 when they were still Bell Labs) runs natively on 386 class systems and under several different operating systems including: Linux, Microsoft's NT, and Solaris.

The line between OS and "emulator" or "program" will get more blurred with JavaOS