Just two decades ago, comprehensive reference books were an upper middle class luxury. Owning a complete volume of any encyclopedia cost at least hundreds, and often thousands, of dollar. That all changed with the birth of the compact disc and the increased availability of home computers. Now, enormous amounts of information are accessible with the click of a button at little to no cost.
Dictionary and Thesaurus Software
Since print dictionaries and thesauri are relatively small books, their popularity hasn't take the kind of massive hit that print encyclopedias have taken. Also, their compact nature makes them less likely to appear as independent software on CD or DVD. However, thanks to the increasing popularity of mobile communication devices, dictionary and thesaurus software is increasingly portable to PDAs, smartphones and other handhelds.
Though the Internet revolution has come close to displacing home-use only encyclopedias in both print and on transportable media, there are still several respected publishers who continue to release CD and DVD versions of their volumes, though most of the content on these volumes is also available via online subscription. Most software encyclopedias include dictionaries and thesaurus software in addition to the typical encylopedic features. Some publishers offer home users special features not available on their online reference pages.
Online Reference Materials
The popularity of the Internet has revolutionized how human beings access their information. There are dozens of completely free Web sites offering reference-oriented content on any number of subjects as well as comprehensive versions of classic encyclopedias like ''Britanicca'' and ''World Book'' that charge a yearly or monthly fee. The Internet could even bee considered the world's largest and most complex reference guide. Below are just some of the nearly endless array of examples of online encylopedic, dictionary and thesaurus resources.