In Lesson 4 we covered email borne viruses, hidden file extensions and email spoofing. This lesson we will go on to cover some of the common interactive elements used on the Internet including Javascript and ActiveX applets, IM (Instant Messaging) and P2P (Peer-to-Peer) networks. We will also discuss cross-site scripting (XSS) and packet sniffing.
About 10 “people years” (or about 60 years ago in “web years” according to the FAQ on Tim Berners-Lee’s web site) ago the World Wide Web was text-based. In 1989 Tim Berners-Lee began creating a global hypertext project. By the summer of 1991 the World Wide Web was born and released to the Internet at large.
The Hypertext Markup Language (HTML)used to create the web pages continued to be refined. By late 1992 Marc Andreessen and the NCSA team created X-Mosaic. Mosaic introduced the “img” tag which allowed graphics to be inserted into the web pages as well. This brought on the explosive growth and popularity of the World Wide Web, however the pages were still static- meaning they only showed whatever they were programmed to show in the first place.
In order to provide more functionality- whether for business or entertainment- companies needed to find a way to make the pages dynamic. They wanted to be able to present new information or update the information on the screen automatically. Active scripting was created to fulfill this need.
Marc Andreessen had left NCSA and formed Netscape Communications by this time. Working with Sun Microsystems, who had just developed Java as a platform-independent programming language, Netscape created LiveScript as a compliment to both HTML and Java that would allow developers to create scripts that run within the HTML code to create content dynamically. In late 1995 they officially changed the name to JavaScript to hitch a ride on the coattails of popularity surrounding Sun’s Java programming language.
Using JavaScript you could take user input, perform calculations, display the current date and time and a slew of other things that make the page change over time or unique from user to user. This sort of dynamic content or content that was unique to the user made the World Wide Web much more interesting than simply viewing static pages.