Ubuntu, Mint, Fedora, RedHat, Debian, Google's Android. Chrome OS, Chromium OS.

Multi-user Operating Systems:
1. It is used in computers and laptops that allow same data and applications to be accessed by multiple users at the same time.
2. The users can also communicate with each other. Windows, Linux and UNIX are examples for multi-user Operating System.

(i) To ensure that a computer can be used to extract what the user wants it do.
(ii) Easy interaction between the users and computers

A mobile operating system controls a mobile device and its design supports wireless communication and different types of mobile applications. It operates 012 smart phones Tablets and Digital Mobile devices.
(i) Google Android
(ii) Apple iOS
(iii) Blackberry
(iv) Symbian

The main purpose of using an operating system:
(i) It controls and coordinates all the activities of a computer system.
(ii) It provides an environment for a computer user to execute programs on computer hardware in a convenient and efficient manner.
(iii) It enables the user to design the application, and also it provides an interface to interact with the computer and controls the execution of all kinds .of programs without knowing the internals of the hardware.
(iv) It interprets the command and instructions to perform the specified tasks.
(v) It coordinates and assigns the compilers, assemblers, utility programs to the users.
(vi) It detects errors present in the hardware and software.
(vii) It maintains the internal time clock.
(viii) It protects itself from being destroyed by any users.
(ix) It serves two major functions
1. Supervision (Prevent errors)
2. Management (Operation and control of I/O devices)
(x) It loads the programs itself into memory so that user can interact with hardware and software.

The Distributed Operating System is used to access shared data and files that reside in any machine around the world using internet / intranet. The users can access as if it is available on their own computer.
The advantages of distributed Operating System are as follows:
(i) A user at one location can make use of all the resources available at another location over the network.
(ii) Many computer resources can be added easily in the network
(iii) Improves the interaction with the customers and clients.
(iv) Reduces the load on the host computer.