Following on from the development and introduction of UNIX and also the creation of the GNU General Public License (GNU GPL), in order to spread software freely, many of the programs required in an OS (such as libraries, compilers, text editors, a UNIX shell, and a windowing system) were completed by the early 1990s, but few elements such as device drivers, daemons, and the kernel were incomplete.
In 1991, Linus Torvalds began to work on MINIX, a Unix-like OS originally developed for academics, whose code was freely available under GNU GPL project. After which the first LINUX kernel was released on 17 September 1991, for the Intel x86 PC systems. This kernel included various system utilities and libraries from the GNU project to create a usable operating system. All underlying source code can be freely modified and used.
Linux is great for small- to medium-sized operations, and today it is also used in large enterprises where UNIX was considered previously as the only option. A few years ago, most big enterprises where networking and multiple user computing is the main concern, didn't consider Linux as an option. But today, with major software vendors porting their applications to Linux, being freely distributed and being installed pretty much on anything from mobile cell phones to supercomputers, the OS has entered the mainstream as a viable option for Web serving and office applications.
Both the main commercial virtualization offerings in VMware’s vSphere and Microsoft’s Hyper-V both support Linux as an operating system and along with Windows is the most popular virtualized operating system within organizations.
Its popularity has increased to include a user base estimated to be in excess of 25 million because of its application in embedded technologies and because it is free and easily available.
I'll be covering Cloud Concerns next time as to understand our Capacity and Performance concerns around cloud, we need to fully understand what the cloud is and its relation to UNIX/Linux systems.