1.2 UNIX |
1.2.1 Birth of UNIX
UNIX was born at Bell Laboratories of AT & T, a telecommunications company. At that time, at Bell
Laboratories, OS called MULTICS was developed as a prior research. Ken Thompson, a researcher, found a
computer that was not used in sideward of the laboratory and installed a small OS on the computer to test the mechanism that he thought. It is said that that was the birth of UNIX.
Because MULTICS was aiming at multifunctionality and high function too much, research and development
was torn down. Ken Thompson created an prototype of UNIX by incorporating the function of MULTICS
into the small OS that he made.
Actually, UNIX was very compactly and worked quickly, then came to be used also for a variety of
experiment projects. It was also used as OS to run the document composition software when software for the document proofreading was needed in AT&T.
Moreover at that time, AT & T was not considering UNIX as a commodity, so its use was freely permitted
only by paying expenses such as postage and media fee. In addition, because we distributed the basic part of UNIX design, which is called source code, as it was, the user who got it could do research, development, change, etc. independently.
1.2.2 Various separation and integration
The distributed UNIX had been subject to free reconstruction. Then, many variant of Unix were created, and the confusion has begun. AT & T has officially begun licensing agreements and has started to manage UNIX.
Since then, only organizations that have signed up with AT & T (and UNIX license management organization) became to able to declare their own OS as UNIX.
Of course, some organizations do not have such a contract. The UNIX OS issued by those organizations is
not official UNIX even though it takes UNIX format. We call them "UNIX like OS" or "UNIX compatible
OS"..
Therefore, even if it is said to a word UNIX, there are correct UNIX in the law that it enters into licensing agreements formally and compatible OS that takes the same form as UNIX exists.
1.2.3 Derivation UNIX
Quite a lot of UNIX including compatible OS has spread like that. It is Berkeley version UNIX to have
exerted a big influence in derivation UNIXs.
Berkeley UNIX is a derived OS which was created by Ken Thompson, the UNIX developer, when he was at
the University of California Berkeley. There are some portions where the design has changed significantly.
As functional update, implementation of IP (Internet Protocol) adopted as communication method inside the US military at that time was also done. UNIX had strong capability in the Internet, because this function existed.
After that, AT & T's UNIX is called System V UNIX and BSD version is called BSD UNIX, and for a long
time they were divided.
1.2.4 Birth of Linux
Many of UNIX had been used by companies, universities, etc. with high licensing fee. Many users dreamed
that they would use it on their personal computer at home. A person who developed UNIX which operates
on a PC actually appeared.
In 1991, an article called "I'm making a UNIX compatible OS now" has flowed on the net. The contributor
was a university student in Finland named Linus Torvalds, who was writing such a program from the learning of computer functions. The program was made public on the network.
The prototype of the program was very primitive, and only people who were familiar with computers were
able to operate. The basic design was similar to UNIX, but it was a proprietary UNIX compatible OS that
does not have the flow of System V or BSD. Necessary tools and so on were combined after that, and it came to operate well as UNIX-compatible OS. This is the birth of Linux.
The most characteristic aspect of the Linux program was its license form. The Linux program adopted a
license format called GPL (GNU General Public License: GNU General Public License). GPL is a software
licensing form proposed by GNU project, characterized by the following contents included.
(You may modify it, but you must disclose the modified content)
Therefore various users was able to get and use it without charge. In addition, because the modification was permitted, it is possible to improve it. However, on the license, there was a condition that you must disclose the content (If it was demanded). As a result, the developing style, that some individuals and organization don't hide improvement result and all user receive the benefits, was completed.
