What is an operating system (OS)?

In the simplest definition, an operating system (OS) is a set of instructions (software) that controls some hardware. These instructions are layered over the kernel accessing the hardware directly and the command line interface (CLI) or graphical user interface (GUI) for the user (normally a human being) to interact with it. These instructions are written (coded) using in different languages from low-level languages (like machine language and assembler) to high-level languages (like C++).

Operating systems have evolved from their early days and surprisingly most modern operating systems were made a good time ago like MVS in 1964, Unix in 1969, BSD in 1977, DOS in 1980, Macintosh (or Mac) in 1984, Windows in 1985 and Linux in 1991.

DEC VT100 terminal
          (DEC VT100 terminal at the Living Computer Museum (apparently
          connected to the museum's DEC PDP-11/70) Date 30 August 2013,
          15:23:56 Source Flickr: IMG_9976 Author Jason Scott Permission
          (Reusing this file) Checked copyright icon.svg This image,
          which was originally posted to Flickr.com, was uploaded to
          Commons using Flickr upload bot on 19:18, 6 November 2013
          (UTC) by Morn (talk).  On that date it was licensed under the
          license below.  w:en:Creative Commons attribution This file is
          licensed under the Creative Commons Attribution 2.0 Generic
          license.  You are free: to share, to copy, distribute and
          transmit the work, to remix, to adapt the work Under the
          following conditions: attribution, You must attribute the work
          in the manner specified by the author or licensor (but not in
          any way that suggests that they endorse you or your use of the
          work).) In the past couple of years, a different approach to operating systems and management of resources uses thin-clients (practically dumb terminals) accessing all shared resources from a server through a web browser — referred to cloud computing (web platforms).

At the same time, computers (microcomputers) have shrunk from huge machines that would fit in a loft (like an IBM System/360 mainframe computers) to machines that fit in your pocket like any of today's mobile phones. Computers are used worldwide for various purposes from web browsing to going to outer space (NASA).

This site takes a high level look at various operating systems used worldwide. It is merely my opinion, the result of curiosity of computer systems and programming. As such, the sole purpose of VintageOS is to document experiences of rebuilding old computer systems and their operating systems and to have fun while doing the latter.

If you are interested in experimenting with any of the operating systems covered in VintageOS, you can create a VDI with VirtualBox (free) or similar application.

Web
          Literacy Skill Sharer, Issued by Webmaker, Nov 17, 2014 On 11/17/2014, I, by means of VintageOS, received Web Literacy Skill Sharer badge from Webmaker, part of the Mozilla Foundation.

"Web Literacy Skill Sharer
Issued by: Webmaker
This badge can be issued to people who have shared a web literacy skill and written about their experience on the web. Here's how to earn this badge:
1) Explore the competencies listed in the Web Literacy Map
2) Choose one of the 15 competencies that you feel especially passionate about
3) Look at the list of skills underpinning that competency, and then share one of those with someone else — either using one of the suggested resources or by inventing your own way of teaching it
4) Share a blog post, video or image online illustrating how you taught the web literacy skill"