Monday, February 23, 2009


Acronym for the American Standard Code for Information Interchange. Pronounced ask-ee, ASCII is a code for representing English characters as numbers, with each letter assigned a number from 0 to 127. For example, the ASCII code for uppercase M is 77. Most computers use ASCII codes to represent text, which makes it possible to transfer data from one computer to another.

For a list of commonly used characters and their ASCII equivalents, refer to the ASCII page in the Quick Reference section.

Text files stored in ASCII format are sometimes called ASCII files. Text editors and word processors are usually capable of storing data in ASCII format, although ASCII format is not always the default storage format. Most data files, particularly if they contain numeric data, are not stored in ASCII format. Executable programs are never stored in ASCII format.

The standard ASCII character set uses just 7 bits for each character. There are several larger character sets that use 8 bits, which gives them 128 additional characters. The extra characters are used to represent non-English characters, graphics symbols, and mathematical symbols. Several companies and organizations have proposed extensions for these 128 characters. The DOS operating system uses a superset of ASCII called extended ASCII or high ASCII. A more universal standard is the ISO Latin 1 set of characters, which is used by many operating systems, as well as Web browsers.

Monday, February 16, 2009

Ajax (programming)

Ajax, or AJAX (Asynchronous JavaScript and XML), is a group of interrelated web development techniques used to create interactive web applications or rich Internet applications. With Ajax, web applications can retrieve data from the server asynchronously in the background without interfering with the display and behavior of the existing page. The use of Ajax has led to an increase in interactive animation on web pages.

Data is retrieved using the XMLHttp Request object or through the use of Remote Scripting in browsers that do not support it. Despite the name, the use of JavaScript and XML is not actually required, nor do the requests need to be asynchronous. The acronym AJAX has thus changed to the term Ajax, which does not represent these specific technologies.

While the term AJAX was coined in 2005, alternative techniques for the asynchronous loading of content date back to the mid 1990s. Java applets were introduced in the first version of the Java language in 1995. These allow compiled client-side code to load data asynchronously from the web server after a web page is loaded.

Monday, February 9, 2009


In computing, a hacker is a person in one of several distinct (but not completely disjoint) communities and subcultures:

* People committed to circumvention of computer security. This primarily concerns unauthorized remote computer break-ins via a communication networks such as the Internet (black hats), but also includes those who debug or fix security problems (white hats), and the morally grey hats. See "Hacker (computer security)".

* A community of enthusiast computer programmers and systems designers, originated in the 1960s around the Massachusetts Institute of Technology (MIT)'s Tech Model Railroad Club (TMRC) and MIT Artificial Intelligence Laboratory. This community is notable for launching the free software movement. The World Wide Web and the Internet itself are also hacker artifacts. The Request for Comments RFC 1392 amplifies this meaning as “person who delights in having an intimate understanding of the internal workings of a system, computers and computer networks in particular." See "Hacker (programmer subculture)".

* The hobbyist home computing community, focusing on hardware in the late 1970s (e.g. the Homebrew Computer Club) and on software (computer games, software cracking, the demo scene) in the 1980s/1990s. The community included Steve Jobs, Steve Wozniak and Bill Gates and created the personal computing industry. See "Hacker (hobbyist)".

Monday, February 2, 2009

Adobe Flash

Adobe Flash (previously called Macro media Flash) is a multimedia platform created by Macro media and currently developed and distributed by Adobe Systems. Since its introduction in 1996, Flash has become a popular method for adding animation and interactivity to web pages; Flash is commonly used to create animation, advertisements, and various web page components, to integrate video into web pages, and more recently, to develop rich Internet applications.

Flash can manipulate vector and raster graphics and supports bi-directional streaming of audio and video. It contains a scripting language called Action Script. Several software products, systems, and devices are able to create or display Flash content, including Adobe Flash Player, which is available for most common web browsers, some mobile phones and other electronic devices (using Flash Lite). The Adobe Flash Professional multimedia authoring program is used to create content for the Adobe Engagement Platform, such as web applications, games and movies, and content for mobile phones and other embedded devices.