Encyclopedia of Computer Science and Technology

Ruby 413tor (the latter can combine feeds or organize them in anewspaper-like format for convenience). RSS readers canbe stand-alone applications or be included with many modernWeb browsers and e-mail clients. Alternatively, Webbasedreaders or aggregators such as NewsGator Online canallow feeds to be read using any Web browser. Readers ofWeb pages can find RSS feeds by looking for a “subscribe”icon or the words RSS or XML. Specialized search enginessuch as Bloglines can also help users find interesting feeds.Additionally, information on the server can also be usedby software to automatically deliver the latest content (seepodcasting).History and DevelopmentForerunners of RSS go back to the mid-1990s, with RDFSite Summary first appearing in 1999 for use on Netscape’sportal. The adoption of RSS by the New York Times in 2002greatly aided the popularization of the format, as did thegrowing number of blogs that needed a way for contributorsand readers to keep in touch. Today Web browsers such asInternet Explorer, Mozilla Firefox, and Safari support RSS.File-sharing services such as BitTorrent can be combinedwith RSS to deliver content automatically to users’ harddrives. An offshoot of RSS called Atom has been less widelyadopted, but offers better compatibility with XML standardsand better management of multimedia content.Further ReadingBloglines. Available online. URL: http://www.bloglines.com/.Accessed November 19, 2007.Calishain, Tara. Information Trapping: Real-Time Research on theWeb. Berkeley, Calif.: New Riders, 2007.Finkelstein, Ellen. Syndicating Web Sites with RSS Feeds for Dummies.Hoboken, N.J.: Wiley, 2005.RSS Advisory Board. Available online. URL: http://www.rssboard.org. Accessed November 19, 2007.Sherman, Chris. “What Is RSS, and Why Should You Care?” SearchEngine Watch, August 30, 2005. Available online. URL: http://searchenginewatch.com/showPage.html?page=3530926.Accessed November 19, 2007.RTF (Rich Text Format)Rich Text Format was developed in the later 1980s by programmersat Microsoft. Its purpose is to allow for interchangeof documents between Microsoft Word and othersoftware, while preserving the original formatting.An RTF file is itself a plain text file containing the documenttext enclosed in control codes that determine the formatting.For example:{\rtf1\ansi{\fonttbl{\f0\froman\fprq2\fcharset0 Times New Roman;}\f0\pardThis is some {\b bold} text.\par}The backslash starts a control code, such as for specifyinga font or a style, such as Times New Roman and boldin the example. Curly brackets { } enclose the text to beaffected by the control code. Thus the example above wouldbe rendered in a word processor as:This is some bold text.Although RTF is an 8-bit format, special escapesequences can be used to specify 16-bit Unicode characters,such as for non-Roman alphabets.Libraries and utilities are available for reading andwriting RTF from most popular programming languages,including Perl, PHP, and Ruby.In practice, RTF created by word processors tends tocontain many control codes needed to ensure compatibilitywith older programs, making the files bulky and not practicableto edit directly. However, saving a file in RTF is agood way to ensure that a document can be used by recipientswho may have, for example, older versions of Word. (Itis quite typical for the latest default Word format to not becompatible with earlier versions.)Further ReadingBurke, Sean M. RTF Pocket Guide. Sebastapol, Calif.: O’Reilly,2003.Microsoft Corporation. Word 2007: Rich Text Format (RTF),Specification, Version 1.9. Available online. URL: http://www.microsoft.com/downloads/details.aspx?FamilyID=DD422B8D-FF06-420 7-B476-6B5396A18A2B. Accessed November 13,2007.RubyRuby is a versatile yet consistent programming languagethat has become popular in recent years, particularly forWeb development. Designed by Yukihiro Matsumoto andfirst released in 1995, Ruby has a compact syntax familiarto many users of Perl and other scripting languages (seePerl and Scripting language), avoiding, for example,the need to declare variable types. However, Ruby is alsoa thoroughgoing object-oriented language somewhat likeSmalltalk (see Smalltalk). Matsumoto has stressed thatthe design of the language is intended to stress being naturaland enjoyable for the programmer, rather than focusingon the needs of the machine.StructureIn Ruby, every data type is an object (see class, data type,and object), even those defined as primitive types in otherlanguages, such as integers and Booleans. Although one canuse the traditional procedural method of defining variablesand then working with them, they are still implicitly treatedas part of the root object called “Self.”Every function is a method that belongs to some class.Thus -5.abs invokes the absolute value method on the integer-5, returning 5. Similarly, “wireless wombat”.lengthwould return the length of the string, 15. Ruby includesmany built-in methods for working with data structuressuch as arrays and hashes, and there are many additionallibraries and applications available.There are Ruby interpreters for all major operating systems.In addition to reading and executing a program from