The capabilities of the Internet have been enhanced and extended by using programming languages with HTML. These languages have been responsible for the dynamic and interactive nature of the Net. New languages and language extensions are being developed to increase the usability of the Internet.
On this page I’ll provide a brief on some of the important languages that have shape the Internet over the years. In brief, there are three types of languages – HTML (which is NOT a programming language, though included here), client-side languages and server-side languages.
HTML (HyperText Markup Language) is the lingua franca of the Internet. It is the language used to develop web pages. Hypertext means that some text in the HTML document carries a link to a different location, which can be on the same page or another page. On clicking this ‘hot spot’, the viewer is transferred to that location. Markup means that specific portions of a document are marked up to indicate how they should be displayed in the browser.
According to purists, HTML is not a language per se, and they are right in one way. HTML simply consists of tags that are placed around elements, which then changes the properties of these enclosed elements. There are hundreds of HTML tags and some of these are proprietary, which means that only some browsers recognize them.
The Common Gateway Interface (CGI) has been around for a long time. It allows the web server software to communicate with other programs running on the server. These external programs are called CGI scripts or CGI programs and are usually written in Perl or ‘C’. CGI programs are generally used to process information submitted by visitors via a form on a web page. For example, you might use the search form on a web site to look for ‘cars’. When you submit your query, the server receives your request, passes it to the CGI program. The program then looks up the search query term in a database and responds with the appropriate result formatted in HTML code.
Developed by Sun Microsystems, Java is a very powerful, object-oriented language. A lot many platform dependency issues have been ironed out with the advent of Java. Thus, Java programs for Unix can be made to run on Windows or the Mac system with little or no effort. Much development is taking place on the Java front with new arrivals like Java Beans, Extended Java Beans, and Java applications for various databases and XML. Using Java servlets one can also develop dynamic Java Server Pages (JSP).
Java can also be seen on the Internet in the form of applets embedded in an HTML page. Applets are small Java programs that run on a Java compatible browser.
Open source, great development environment – PHP is a cult. This has been the answer of open source programmers to Microsofts ASP. PHP not only carries all the goodness of ASP but also is more secure and handles databases more easily. It is a known fact that PHP on Apache Web server runs faster than ASP. PHP code is embedded inside the HTML page and can link to databases to generate dynamic HTML content. Furthermore, PHP scripts can be made to run on any operating system with little or no modification.
The eXtensible Markup Language is a web page developing language that enables programmers to create customized tags. These customized tags can provide the much-needed functionality not available with HTML. XML documents can be accessed using JSP, PHP etc.
There are several other languages on the Internet such as Perl, Python, VRML (Virtual Reality modeling Language), awk etc., which I have not discussed here. You can search for them on your favorite search engine.
Though the digital data on the Internet resides on millions of interconnected servers, the net itself is just data transfer which takes place by electrons and radio waves. Russell Seitz, a physicist, tried to find the weight of the Internet based on this. His calculations, using Einstein's famous e = mc2 formula, revealed that the mighty Internet weighs as much as a strawberry. [more...]