In this lesson we're going to look at the history of Linux. We will be learning some new terms as we do. Then we will look at the pros and cons of Linux. Finally we will discuss some of the common uses for linux.
Before Linux was created we had Unix. Unix is an operating system developed in 1969 at AT&T Bell Labs. Unix was owned by AT&T and as such had to be purchased before you could use it. An operating system is the program that runs all other applications and controls how those applications interact with the hardware.
Programmers would write applications for Unix and share them with other programmers. They would share the source code, source code is a text file that contains all the instructions to be executed by the computer. It was a very exciting time, programmers were learning the capabilities of the hardware and programing languages. When they would do something impressive they would share the source code with others. There was a sense of pride in the process of sharing your work with others. Then others would build on your source code and add improvements and share the results. This sharing helped the computer industry grow.
As time went on companies starting to release compiled versions of applications without the source code. Compiled versions were the result of running the source code through a compiler and producing an executable file in machine code. With an executable you could run the software, but not see how it was written.
There was a split in the computer industry about what method was right. One side wanted to share all source code so everyone could benefit from seeing how things work. Open Source is the process of releasing your source code with your program so others can see and edit it. The other side wanted to protect their source code to prevent others from taking their product. Companies like Microsoft and IBM did not release their source code, this is known as Closed Source and is common today.
Torvalds was creating what would become the Linux Kernel. A kernel is the center of the operating system and controls how applications gain access to the hardware. Later Torvalds would release the Linux Kernel under the GPL completing the vision of a free and open source operating system with applications. The Linux Kernel wasn't complete without all the application under the GPL, and the GPL applications weren't complete without a kernel to run them.
There are many benefits to using Linux, they include:
There are drawbacks to Linux as well.
In the early years of Linux it was difficult to install on a computer. A normal user would struggle with the install. This lead to several companies putting together the kernel with applications and utilities in an easy to install package. These collections of applications combined with the kernel are called distributions. There are many distributions available today specializing in many different areas.
You used to be able to walk into a store and purchase a boxed copy of a Linux distribution. Today the most common method for acquiring a Linux distribution is by downloading it from the Internet. You download an ISO, or disk image, and either burn it to a DVD/CD, or build a USB bootable disk.
Once installed you can use Linux for many things. You can use it as a desktop client like you would a computer running Windows client. You can also use it as a server. Linux can provide many services including:
If you're new to Linux you can easily try it out without disrupting your current computing environment. Many distributions of Linux come in a live CD version. With a live CD you can start your system from the CD and run Linux without touching the contents of your hard drive. This gives you the ability to try it out without destroying your current system. Once you are done in Linux shut down the computer, take the CD out and turn the computer back on, you'll return to your normal operating system.
If you decide you want a more permanent installation of Linux you can install it to your hard drive. One method for doing this is to set your computer up in dual boot mode. In Dual Boot mode you have two operating system installed on your computer and you pick one when you turn on your computer.
If you are setting up a computer as a server then dual boot isn't a good option. You can also set up Linux to be the only operating system on the computer.
Each distribution of Linux can vary in how the installation is performed. We will be installing Linux from a live CD. When we start up from the live CD we'll see an icon on the desktop to install Linux to the hard drive.