{
    "0":{
        "title": "Introduction"
        ,"content": {
            "0": {
                "subtitle": "Why this guide?"
                ,"content": "Many people still believe that learning Linux is difficult, or that only experts can understand how a Linux system works. Though there is a lot of free documentation available, the documentation is widely scattered on the Web, and often confusing, since it is usually oriented toward experienced UNIX or Linux users. Today, thanks to the advancements in development, Linux has grown in popularity both at home and at work. The goal of this guide is to show people of all ages that Linux can be simple and fun, and used for all kinds of purposes."
            }
            ,"1": {
                "subtitle": "Who should read this book?"
                ,"content": "This guide was created as an overview of the Linux Operating System, geared toward new users as an exploration tour and getting started guide, with exercises at the end of each chapter. For more advanced trainees it can be a desktop reference, and a collection of the base knowledge needed to proceed with system and network administration. This book contains many real life examples derived from the author's experience as a Linux system and network administrator, trainer and consultant. We hope these examples will help you to get a better understanding of the Linux system and that you feel encouraged to try out things on your own.\n\nEverybody who wants to get a "CLUE", a Command Line User Experience, with Linux (and UNIX in general) will find this book useful."
            }
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        }
    }
    "1":{
        "title": "What is Linux?"
        ,"content": {
            "0": {
                "subtitle": "History"
                ,"content": {
                    "0": {
                        "subsubtitle": "UNIX"
                        ,"content": "In order to understand the popularity of Linux, we need to travel back in time, about 30 years ago...\nImagine computers as big as houses, even stadiums. While the sizes of those computers posed substantial problems, there was one thing that made this even worse: every computer had a different operating system. Software was always customized to serve a specific purpose, and software for one given system didn't run on another system. Being able to work with one system didn't automatically mean that you could work with another. It was difficult, both for the users and the system administrators.\nComputers were extremely expensive then, and sacrifices had to be made even after the original purchase just to get the users to understand how they worked. The total cost per unit of computing power was enormous.\nTechnologically the world was not quite that advanced, so they had to live with the size for another decade. In 1969, a team of developers in the Bell Labs laboratories started working on a solution for the software problem, to address these compatibility issues. They developed a new operating system, which was\nSimple and elegant.\nWritten in the C programming language instead of in assembly code.\nAble to recycle code.\nThe Bell Labs developers named their project "UNIX."\nThe code recycling features were very important. Until then, all commercially available computer systems were written in a code specifically developed for one system. UNIX on the other hand needed only a small piece of that special code, which is now commonly named the kernel. This kernel is the only piece of code that needs to be adapted for every specific system and forms the base of the UNIX system. The operating system and all other functions were built around this kernel and written in a higher programming language, C. This language was especially developed for creating the UNIX system. Using this new technique, it was much easier to develop an operating system that could run on many different types of hardware.\nThe software vendors were quick to adapt, since they could sell ten times more software almost effortlessly. Weird new situations came in existence: imagine for instance computers from different vendors communicating in the same network, or users working on different systems without the need for extra education to use another computer. UNIX did a great deal to help users become compatible with different systems.\nThroughout the next couple of decades the development of UNIX continued. More things became possible to do and more hardware and software vendors added support for UNIX to their products.\nUNIX was initially found only in very large environments with mainframes and minicomputers (note that a PC is a "micro" computer). You had to work at a university, for the government or for large financial corporations in order to get your hands on a UNIX system.\nBut smaller computers were being developed, and by the end of the 80's, many people had home computers. By that time, there were several versions of UNIX available for the PC architecture, but none of them were truly free and more important: they were all terribly slow, so most people ran MS DOS or Windows 3.1 on their home PCs."
                    }
                    ,"1": {
                        "subsubtitle": "Linus and Linux"
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                    }
                }
            }
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        }
    }
}