Initially, it was written entirely in the assembly language as a common practice at that time. Later on, in 1973, Unix was re-written in the programming language C by Dennis Ritchie.
Linux was developed as a free operating system for the Intel x86-based personal computers. Since then, it has been ported more towards computer hardware platforms than any other operating system.
It is a leading operating system on the servers and other big iron systems like mainframe computers and supercomputers. As of June 2013, more than 95% of the world’s 500 fastest supercomputers started running on some variant of Linux.
Linux also can run on embedded systems, these are the devices whose operating system is built into the firmware and is highly tailored to the system; this also include network routers, facility automation controls, mobile phones, tablet computers, televisions and video game consoles. Android, which is widely used operating system for mobile devices nowadays, are built on to the top of the Linux kernel.
Some components of the Linux system are:
A bootloader, example GNU GRUB or LILO is a program that is executed by the computer when it is turned on, and loads the Linux kernel into its memory.
An init program the first process that is launched by the Linux kernel, is at the root of the process tree. We can also say, all processes are launched through init. It starts the processes such as system services and login prompts. Software libraries that contain code used by running processes.
On Linux systems using ELF-format executable files, the dynamic linker manages use of dynamic libraries that is “ld-linux.so”. The most commonly used software library on the Linux systems is GNU C Library. If the system is set up to compile software themselves, header files will be included to describe the interface of installed libraries.
User interface programs like command shells or windowing environments are also available here.