Historical Development and Status Quo of UNIX

At present, Windows operating systems have occupied desktop computers, while UNIX still plays an irreplaceable role in the field of high-end workstations and servers. Especially for Internet servers, the high performance and high reliability of UNIX are not comparable to those of Windows NT computers.

However, UNIX is not a separate product of a manufacturer. In the long-term development process, a variety of different versions have been formed. Although the basic operation commands are similar, however, the differences may cause some confusion for users and network administrators who do not know much about the Unix development process, resulting in problems in use or management.

Unix development stage

In general, the development of UNIX can be divided into three stages:

The first stage is the initial development stage of Unix. Since the 1969 s, at&t Bell Labs have created a UNIX operating system, and at the beginning, it has only been used and improved in the laboratory, at this stage, Unix has evolved from version 1 to version 6. At the same time, Unix also allows universities and research institutions to obtain UNIX source code for research and development by distributing licenses. The most important event in this phase is that the Unix author uses the C language to rewrite the Unix source code, making UNIX very portable.

The second stage was in 1980s, a rich period of Unix development. After the development of UNIX to version 6, at&t continued to develop its internal Unix Version 7, at the same time, an external release version has also been developed, but it is called by using the system plus the Roman letter as the version number. Both system III and System V are important UNIX versions. In addition, other vendors and scientific research institutions have all improved Unix. Among them, the BSD version of UC Berkeley is the most famous, and many commercial UNIX versions have been derived from 4.2bsd. During this period, the Internet began to study, while bsd unix first implemented TCP/IP, making the Internet and Unix closely integrated.

The third stage is the perfection stage of UNIX, from 1990s to the present. After at&t launched System V Release 4 (the fourth official release of the fifth version), IT and Berkeley's 4.3bsd have formed two major UNIX genres. At this time, at&t realized the Unix value, so he sued many vendors including Berkeley. Berkeley had to launch 4.4bsd Lite that did not contain any at&t source code, this legal lawsuit also led many UNIX vendors to shift from bsd to the system v genre.

Another event in this period was the emergence of Linux. A completely free and Unix-compatible operating system runs on a very popular PC hardware. Linux already has more than 5 million users, making it the second largest operating system after windows.

Important UNIX versions

SunOS and Solaris:

Sun is the earliest workstation vendor, but has been continuously developing in the Unix workstation field. Currently, sun's workstation products and Internet Server products are widely used in Chinanet. Its operating system SunOS is developed based on 4.2bsd until SunOS 4. However, Sun switched the development of the operating system to system v. The new version is Solaris 2 or SunOS 5. Therefore, SunOS 4 can also be called Solaris 1.0, however, SunOS 4 and Solaris 2 belong to two schools, and the difference is quite large.

Sun's Solaris is mainly developed for its processor, or for the Intel Platform, Solaris x86. Compared with Solaris running on workstation, Solaris x86 has poor performance. The latest Solaris version is 2.7, or Solaris 7.0. This kind of trick to use the OS version is just a commercial hype. However, sun's efforts in the Unix field have become the most dynamic UNIX commercial manufacturer, and Solaris is also the most promising commercial UNIX version.

IRIX 6.x:

IRIX 6.x is SGI's UNIX, which is also a UNIX System V-based product. SGI's Unix graphics workstation is a top-level product in the graphic image processing field. This is because SGI has excellent hardware performance. In terms of software, SGI has developed the image processing software under the workstation, become a leader in this field. SGI's leading position in the graphic image field masks his efforts as a Unix vendor in the operating system field. In fact, they are still producing supercomputers, it has unique research on multi-processor, parallel computing, and other heavy-load computing.

In the Unix field, IRIX is not the most dynamic version, but is more concerned about stability. With their excellent hardware cooperation, SGI's server performance is also a top-notch product in Unix servers.

Linux and FreeBSD:

Although UNIX is very open, its kernel code won't be available in 1980s. The easiest code to get is minix, a system written for educational purposes, which is far from a mature system. Linus in Finland decided to write an independent operating system, so a notice was published on the Internet. The Linux System was developed quickly with the help of many Internet enthusiasts and achieved great success. Linux has nothing to do with the source code of other UNIX systems. Strictly speaking, it can only be regarded as a counterfeit product. However, Linux developers come from the entire Internet and have a variety of Unix systems. Therefore, Linux also has a variety of UNIX advantages, which are not inferior to commercial products in terms of performance.

Linux only refers to the operating system kernel. There are many Linux versions using this kernel, such as RedHat Linux, Debian Linux, and slackware Linux. At present, the Linux kernel has been developed to Version 2.2. The released versions include RedHat 5.1 and Debian 2.0.

Due to the popularity of Linux, the original BSD researchers also planned to create a free BSD system running on Intel Platform, resulting in a FreeBSD system.

FreeBSD inherits the mature BSD code, so it is very good in terms of stability and reliability, and therefore favored by small companies, and soon became the second largest free operating system after Linux. FreeBSD runs on ftp.cdrom.com, the largest FTP server on the internet, Yahoo.com on the WWW node, and other busy sites. The popular 163.netand 371.net in China are also built on FreeBSD. Since FreeBSD and Linux are operating systems running on Intel platforms, obfuscation may often lead to a much-known Linux operating system that runs FreeBSD.

SCO openserver and unixware:

Sco unix is a well-known Operating System in China because it uses Intel's platform and entered the Chinese market earlier. Its history can be traced back to the xienx developed by Microsoft. xienx is a unix v 6-based system running on the Intel Platform. Later, the xienx Development Department established SCO independently, sco unix is developed based on at&t system vr3.2. Its latest version is SCO openserver 5.0.4, which enhances the graphic interface. At this time, at&t has sold their UNIX Department usl (UNIX System Laboratory) to Novell, whose Unix was renamed unixware, but Novell is facing business problems, I had to sell unixware to SCO again.

One important move Novell made after purchasing unixware was to present the Unix trademark to a non-profit UNIX organization X/open, ending usl's dispute with BSD and other vendors. Now unixware has become the next-generation product of SCO, and openserver has entered the maintenance period.