On this day, 34 years ago, August 25, 1991 (July 16, 1991 in the lunar calendar), the Linux operating system was born. The birth, development and growth of the Linux operating system have always relied on five important pillars: the UNIX operating system, the MINIX operating system, the GNU Project, the POSIX standard and the Internet. In 1981, IBM introduced the microcomputer IBPC, the first personal computer (microcomputer). 1981-1991 The MS-DOS operating system has been the dominant operating system on microcomputers during the years. In 1991, the GNU Project (open source project) had developed many tools and software. The most anticipated GnuC compiler has emerged, but no free GNU operating system has yet been developed. Even MINIX began to have copyright and needed to be purchased to get the source code. In April 1991, Linus began planning and began writing its own operating system. At first, his purpose was simple, just to learn the programming techniques under the protected mode operation mode of the Intel386 architecture. But the development of Linux later completely changed his original intention. In early 1991, Linus began learning the minix operating system on a 386sx-compatible microcomputer. Through learning, he gradually became unable to satisfy the existing performance of the minix system and began to plan to develop a new free operating system. According to the news released by Linux on the comp.os.minix newsgroup, we can know how he gradually went from learning the minix system to developing his own Linux. Starting in April 1991, Linus spent almost all of his time studying the 386-minix system (hackthe kernel) and trying to port GNU software to the system. On April 13, 1991, Linus announced on comp. os. minix that he had successfully ported bash to minix. On July 3, 1991, the first Linux-related news was published on comp.os.minix (of course, the name Linux didn't exist at this time, and Linus might have in mind at that time was FREAX, which means grotesque, monster, whimsical, etc. in English). It revealed that he was developing a Linux system and had already thought of achieving compatibility with POSIX(the international standard for UNIX) at the beginning of Linux. In Linus's next message, on August 25, 1991, he asked all minix users "What would you like to see in minix?" ("What would you most like to see in minix?"), In this news, he revealed for the first time that he was developing a (free)386(486) operating system, and said that it was just an interest, that the code would not be big, and that it would not be as professional as GNU's Nagken Thompson and Dennis Rich. The idea of developing a free operating system has been in the works since April. I hope you can feedback some information on what you like and don't like in the minix system. Due to practical and other reasons, the newly developed system is very similar to minix at first (and uses the minix file system), and bash(version 1.08) and gcc(version 1.40) have been successfully ported to the new system, and will be available in a few months. Linus stated that the operating system he developed did not use a line of minix source code; Moreover, due to the use of 386's task switching feature, the operating system is not easy to portable (not portable), and only AT hard drives can be used. Linus did not consider the portability of Linux at the time. But Linux can run on almost any hardware architecture. On October 5, 1991, Linus released a message on the comp. os. minix newsgroup, officially announcing the birth of the Linux kernel system (Freeminix-likkekernelsources for 386-AT). This news can be called the birth declaration of Linux and has been widely circulated. So October 5th was a special day for the Linux community, and many later versions of Linux chose this day when they were released. So it is no accident that Red Hat chose this date to release its new system. Although the future development of Linux completely exceeded Linus's expectations, it always adhered to the rules of open source. Therefore, in the face of the powerful offensive of the Windows system, Linux is like an invincible cockroach. Not only is it not dead, but more and more. Currently, there are about 300 Linux distributions. The many versions far exceed the scope of other operating systems, and the software industry is very open. You can customize anything under Linux (as long as you have the technology), which is unimaginable under Windows or Mac. Torvalds must have been surprised by the speed at which Linux and a range of related software packages can be "big and professional." He had a very good opportunity. The Internet is just in its infancy, making it easier and cheaper for developers around the world to collaborate via email. At the same time, everyone from ordinary programmers to technology companies is looking for alternatives to Microsoft Windows, so the demand is very strong. Torvalds designed Linux with a modular concept, which makes it easier for Linux to improve performance and adapt to more computers than Windows. Today, Linux and its branch systems are the most widely used operating systems in the world. From small medical devices to large cloud computing servers, Linux is the operating system that drives these hardware. Its biggest success is undoubtedly in the smartphone operating system. In 2015, about 1.5 billion smartphones were sold worldwide, and about three-quarters of the operating system ran Android, which was modified based on Linux. Even Microsoft, which once compared open source software to cancer, now publicly professes its love for Linux. However, Torvalds 'biggest contribution is at the organizational level. He showed the possibility of forming a global community of developers who were originally considered outliers in the crowd, but in this community they "made" a series of world-changing products. Nowadays, there are more than one million open source projects, and the vast majority of them can find their home on GitHub. GitHub already hosts 10 million developers and 26 million projects (not only code, but also text and data). In many software markets, especially non-operating system software development, open source code has become a popular way of writing code. For example, Apache in servers, Hadoop in data analysis, OpenStack in cloud computing, etc. If these open source projects disappear, the Internet may also stop with a scream. But open source software is not a complete success. The obvious fact is that it's hard to make money from free products. Only one Linux company has become a giant, Red Hat, which is expected to generate $2 billion in revenue in fiscal 2015, with the vast majority of revenue coming from selling open source operating systems and support services for open source software. The biggest beneficiaries of open source software are companies with a large number of data centers, such as Amazon, Facebook, Google (Weibo), etc. Because they do not have to pay for open source software, they can provide cheap cloud computing services to enterprises and ordinary consumers. In return, many companies have also become the largest contributors to open source projects, sometimes requiring the entire company's internal software package to be placed in the open source community. For example, Google recently opened up Kubernetes, a project that can turn a group of computer devices into a supercomputer. As computing increasingly moves to the cloud, open source software seems irrelevant. One reason is cloud computing's flexible and convenient purchase method and simple deployment model. Despite this, Linux and its followers are still holding on, and even the founders fade out of sight. In the early days of Linux development, Torvalds acted as the final arbiter of decision-making. Now, he no longer seems to be worried about his status as a "leader." At a recent conference, he was no longer so enthusiastic about whether Linux could continue to play a role in the Internet of Things era. Perhaps, for a 46-year-old man, Torvalds is already thinking about post-Linux life, so will he retire when his "child" is 25?