Wiktionary (from the words wiki and dictionary) is a multilingual, web-based project to create a free content dictionary, available in 158 languages. Unlike standard dictionaries, it is written collaboratively by volunteers, dubbed "Wiktionarians", using wiki software, allowing articles to be changed by almost anyone with access to the website.

Like its sister project Wikipedia, Wiktionary is run by the Wikimedia Foundation. Because Wiktionary is not limited by print space considerations, most of Wiktionary's language editions provide definitions and translations of words from many languages, and some editions offer additional information typically found in thesauri and lexicons. Additionally, the English Wiktionary includes Wikisaurus, a category that serves as a thesaurus, including lists of slang words, and the Simple English Wiktionary, compiled using the Basic English subset of the English language.

The goal of Wiktionary is to eventually define "all words in all languages."

Wiktionary was brought online on December 12, 2002, following a proposal by Daniel Alston and an idea by Larry Sanger, co-founder of Wikipedia. On March 28, 2004, the first non-English Wiktionaries were initiated in French and Polish. Wiktionaries in numerous other languages have since been started. Wiktionary was hosted on a temporary URL (wiktionary.wikipedia.org) until May 1, 2004, when it switched to the current full URL. As of May 2009^[ref], Wiktionary features well over 5 million entries across its 272 language editions. The largest of the language editions is the English Wiktionary, with over 3 million entries. The French Wiktionary is the second largest with over 2.2 million entries. Nineteen Wiktionary language editions now contain over 100,000 entries each.

The 100: A Ranking of the Most Influential Persons in History is a 1978 book by Michael H. Hart, reprinted in 1992 with revisions. It is a ranking of the 100 people who, according to Hart, most influenced human history.

The first person on Hart's list is the Prophet of Islam Muhammad. Hart asserted that Muhammad was "supremely successful" in both the religious and secular realms. He also believed that Muhammad's role in the development of Islam was far more influential than Jesus' collaboration in the development of Christianity. He attributes the development of Christianity to St. Paul, who played a pivotal role in its dissemination."

The 1992 revisions included the demotion of figures associated with Communism, such as Vladimir Lenin and Mao Zedong, and the introduction of Mikhail Gorbachev. Hart took sides in the Shakespearean authorship issue and substituted Edward de Vere, 17th Earl of Oxford for William Shakespeare. Hart also substituted Niels Bohr and Henri Becquerel with Ernest Rutherford, thus correcting an error in the first edition. Henry Ford was also promoted from the "Honorary Mentions" list, replacing Pablo Picasso. Finally, some of the rankings were re-ordered, although no one listed in the top ten changed position.