共用方式為


Introduction to Web Dev – Internet History

This is the first article in a series about Web Development exploring the origins of the Internet, the birth of the Web and improvements in user experience from HTML to Silverlight.

Origins of the Internet and the birth of the Web

The origins of the Internet can be traced back to the creation of the first packet switching network by the United States Department of Defence Advanced Research Projects Agency in 1969. The ARPANET initially used the 1822 protocol which supported basic data transmission and receipt acknowledgement but proved inadequate at handling multiple connections to different applications on the same host. The first message to be sent using ARPANET was “Lo”, the intention was to send the word “Login” but the system crashed after the first two letters.

The 1822 protocol was replaced by the NCP (Network Control Program) protocol which supported several technologies still used today such as FTP (File Transfer Protocol) and Email. In fact the first network email is thought to have been sent by Ray Tomlinson between two machines sitting side by side but connected only by ARPANET. It was Ray Tomlinson who introduced the use of the @ sign to separate account and domain names in email addresses.

In 1983 TCP/IP replaced the NCP protocol on ARPANET allowing communication with other similar networks. In 1985 the NSF (National Science Foundation) funded the creation of several supercomputer centres at key US universities and in 1986 created a network between them using the TCP/IP protocol called the NSFNET. Network traffic across the NSFNET grew exponentially and the backbone was upgraded to 1.5M/bits in 1988. At the same time the network was opened up to commercial interests with the NSFNET connected to the commercial MCI Mail system in 1989. The Internet was born.

Meanwhile at CERN (Conseil Européen pour la Recherche Nucléaire) Tim Berners-Lee was working on a project based on the concept of hypertext to facilitate the sharing of research amongst his colleagues. In 1989 CERN was the biggest Internet node in Europe and Lee saw the potential that hypertext had if linked with the TCP/IP and DNS protocols. In 1989 he put forward a proposal for the creation of the ‘World Wide Web’ for which he built the first Web browser, editor and server. The first Web site was published on the 6th August 1991; it featured information about the Web and a list of other sites which was maintained by Lee. In 1993 CERN announced that the World Wide Web would be free to use and in the same year the graphical Web browser Mosaic was released. Both of these things caused exponential growth of the Web and led to it becoming the most popular Internet protocol.

1993 to now; Developments in Web technology

When the Web was first created browsers did not support inline images, instead users would click a link to the image file which would then open in a new window. However in 1993 the Mosaic Web browser was released implementing inline image support and a much friendlier user interface. The release of Mosaic made the Web more consumer-friendly giving it mass appeal. As such Mosaic is often credited with the early growth of the Web. In fact the basic design of the browser has changed little in the last 15 years.

In 1994 a new browser called Netscape Navigator was released, this added some new features that the Mosaic browser didn’t have. The key thing that Netscape offered over Mozilla was its ability to display Web sites before all the content had downloaded. Where Mozilla would wait until all html and images had been downloaded (which could take some time over dial up connections) Netscape began rendering the content as soon as the connection was made. This gave Netscape the edge and led to it having over 70% share of the browser market by 1996.

Through the 90’s many new features were developed including support for frames and JavaScript. Microsoft licensed the original Mosaic code and launched a rival browser; Internet Explorer. Initially the two browsers battled it out for market share but as Web sites became more complex (utilising more JavaScript and graphics) and Internet Explorer matured Netscape’s share reduced dramatically. Today the two most popular browsers are Internet Explorer and Mozilla Firefox both supporting a similar set of features and enabling rich user experiences.

As browsers have developed so have the platforms for Web development allowing authors to create content a world apart from the text only pages seen back in the early days of the Web.

Initially JavaScript enabled some basic interaction with the user on the client-side by allowing manipulation of the DOM (Document Object Model) on the fly. This functionality was complemented with server-side scripting which allowed data to be retrieved and stored on the server allowing the customisation of web pages for individual users and reliable session persistence. Server side technology offered the huge benefit of browser independence as all code was executed on the server and simple html outputted to the client. The key server side technologies were PHP (Personal Home Page) and ASP (Active Server Pages) both technologies can be implemented by writing the code in line with the HTML. ASP is now depreciated and has been replaced by ASP.NET an object orientated server side technology based on .NET.

A common way to define the user experience provided by Web sites is to classify them as either Web 1.0 or Web 2.0. The above technologies alone tend to be used to create Web 1.0 experiences where users navigate largely static pages where data is submitted and updated with a page refresh. Web 2.0 refers to pages that implement the same technologies (along with XML) in a new way allowing pages to be updated dynamically without refreshes. The combined use of these technologies is knows as AJAX (Asynchronous JavaScript and XML). A technology called CSS (Custom Style Sheets) also allows the formatting and data of web pages to be separated allowing greater flexibility in design and manipulation.

Two other technologies which allow greater levels of interaction as well as much improved graphical capability are Adobe Flash and Microsoft Silverlight. Both technologies allow the creation of complex animation including video streaming whilst still allowing server side communication.

Over the coming months I will help you begin Web development from setting up hosting and implementing server-side code right through to cutting edge user experiences using AJAX and ultimately Silverlight.

Technorati Tags: Internet,ASP.NET,Browsers,Web Development,Internet History

Comments

  • Anonymous
    March 17, 2008
    Those of you who have been following my series on Microsoft Web development (see below) you may be interested