This paper defines the concept of ‘open source’ and ‘closed source’ web technologies. This paper gives a detailed explanation of ‘open source’ web technologies while comparing it with its counterpart ‘closed source’ technologies. Various misconceptions about ‘open source’ web technologies are clarified. Lastly, advantages and disadvantages of ‘open source’ web technologies are highlighted. The paper concludes that, the rate of adoption of open source web technologies - is growing and accelerating rapidly. ‘Open source’ software’s (for example, Google technologies; free mobile applications) are looking more and more compelling day by day. Companies, Governments and general public are adopting them rapidly across the world.