Encyclopedia of Computer Science and Technology

Torvalds, Linus 477texting and instant messagingAlthough they use different devices and formats, textmessaging on cell phones and PDAs and instant messagingthrough online services have much in common. Bothinvolve sending short messages to other users who canreceive them and reply as soon as they are online. (Thisis an ad hoc connection that differs from a chat room [seechat, online] in that the latter is an established locationwhere people go to converse with other members. It alsodiffers from an online discussion group [see conferencingsystems and netnews and newsgroups] where messagesare posted and may be replied to later, but there is noreal-time communication.)Text messaging or texting uses a protocol called ShortMessage Service (SMS), which is available with most cellphones and service plans as well as PDAs that have wirelessconnections. When a user sends a message to a designatedrecipient, it goes to a service center where it isrouted to the destination phone; if that phone is not connected,the message is stored and retried later. Typicallymessages are limited to 160 characters, though up to sixor so messages can be concatenated and treated as a longermessage.While texting did not become popular until the late1990s, instant messaging began in the 1970s as a way formultiple users on a shared computer or network (such asa UNIX system) to communicate in real time using commandssuch as send and talk (the latter being more conversational—seechat, online). In the late 1980s and early1990s, various dial-up services (see America Online andonline services) provided for sending text messages (AOLwas the first to use the term instant messages for its facility).By the mid-1990s instant messaging was well established onthe Internet, often employing a graphical user interface, aswith ICQ and AOL Instant Messenger (AOL later acquiredICQ as well).There have been efforts to allow users of different instantmessaging systems to communicate with one another, butresistance on the part of the proprietary networks (oftenciting security concerns) has hobbled this process thus far.Instant messaging has also been implemented as an applicationfor phones and other mobile devices (an effort headedby the Open Mobile Alliance). Generally this involvesreworking the IM software to use the SMS text service tocarry messages.Cultural ImpactBetween 2000 and 2004 the numbers of text messages sentworldwide soared from 17 billion to 500 billion. At about adime a message, texting became a major source of revenuefor phone companies. Since then, texting has continuedto grow, particularly in parts of Europe, the Asia-Pacificregion (particularly China), and Japan (where it has largelybecome an Internet-based service).In the United States texting is most popular amongteenagers (see young people and computing). It is notuncommon to see a bench full of teens talking excitedly toone another while carrying on simultaneous texting withunseen friends in what, to many adult onlookers, appearsto be an incomprehensible code, their conversation perhapsending with ttyl (talk to you later).Loosely affiliated groups communicating by text (seeflash mobs) have organized everything from “happenings”to serious protest campaigns (as in the anti-WTO [WorldTrade Organization] demonstrations in Seattle in 1999 andin the Philippines uprising in 2001.)The popularity of texting has increasingly attracted theattention of fraudsters (see phishing and spoofing andspam) as well as more legitimate marketers.Further ReadingAll about Instant Messengers. Available online. URL: http://aboutmessengers.com/. Accessed November 29, 2007.Hord, Jennifer. “How SMS Works.” Available online. URL: http://communication.howstuffworks.com/sms.htm. AccessedNovember 29, 2007.Le Bodic, Gwenael. Mobile Messaging Technologies and Services:SMS, EMS and MMS. 2nd ed. New York: John Wiley and Sons,2005.Rheingold, Howard. Smart Mobs: The Next Social Revolution. Cambridge,Mass.: Perseus Books, 2003.SMS Speak Translator. Available online. URL: http://smspup.com/smsSpeak.php. Accessed November 29, 2007.“Web Messengers Handbook.” Available online. URL: http://web2.ajaxprojects.com/web2/newsdetails.php?itemid=35. AccessedNovember 29, 2007.Torvalds, Linus(1969– )FinnishSoftware DeveloperLinus Torvalds developed Linux, a free version of the UNIXoperating system that has become the most popular alternativeto proprietary operating systems.Torvalds was born on December 28, 1969, in Helsinki,Finland. His childhood coincided with the microprocessorrevolution and the beginnings of personal computing.At the age of 10, he received a Commodore PC from hisgrandfather, a mathematician. He learned to write his ownsoftware to make the most out of the relatively primitivemachine.In 1988, Torvalds enrolled in the University of Helsinkito study computer science. There he encountered UNIX, apowerful and flexible operating system that was a delightfor programmers who liked to tinker with their computingenvironment. Having experienced UNIX, Torvalds couldno longer be satisfied with the operating systems that ranon most PCs, such as MS-DOS, which lacked the powerfulcommand shell and hundreds of utilities that UNIX userstook for granted.Torvalds’s problem was that the UNIX copyright wasowned by AT&T, which charged $5,000 for a license to runUNIX. To make matters worse, most PCs weren’t powerfulenough to run UNIX anyway.At the time there was already a project called GNUunderway (see open source and Stallman, Richard). TheFree Software Foundation was attempting to replicate all thefunctions of UNIX without using any of AT&T’s proprietary