World Fastest OS is Here !

Elementary OS
A fast and open replacement for Windows and OS X is a Linux distribution based on Ubuntu. It makes use of a desktop with its own shell named Pantheon,and is deeply integrated with other elementary OS applications like Plank (a dock), Midori (the default web browser) and Scratch (a simple text editor). This distribution uses Gala as its window manager,which is based on Mutter.The distribution initially started as a set of themes and applications designed for Ubuntu which later turned into its own Linux distro. Being Ubuntu-based, it is compatible with its repositories and packages and uses Ubuntu’s own software center to handle installation/removal of software. Its user interface aims at being intuitive for new users without consuming too many resources.
Features

Supported on Mac & PC
Its Free
Terminal
Multitasking view and workspace switcher
New lightdm lock screen
Top Panel
Quick access to privacy settings
Integrated firewall
Online accounts
Start Up Application management
Upgraded version of default applications
Many more features

[Hint : Its a Mixture of Ubuntu and Mac OS X]
Guide

Download the ISO from given link below
Burn it on USB[if you don’t know how to create bootable USB then read this guide : Click Here]
Install It Usually..[If you dont know how to install it then read this guide and : Click Here] [Hint : Its installation process is like Ubtuntu]
Done