1. Copyright – This is only for a limited time. The exclusive rights are not absolute but limited by limitations and exceptions including fair use. A major limitation on copyright is that copyright protects only the original expression of ideas, not the underlying ideas themselves. Copyright is a form of intellectual property, applicable to certain forms of creative work. Some, but not all jurisdictions require "fixing" copyrighted works in a tangible form. These rights frequently include reproduction, control over derivative works, distribution, "moral rights" such as attribution. Copyrights are considered territorial rights, which means that they do not extend beyond the territory of a specific jurisdiction. While many aspects of national copyright laws have been standardized through international copyright agreements, copyright laws vary by country. Typically, the duration of a copyright spans the author's life plus 50 to 100 years. Most recognize copyright in any completed work, without formal registration. Generally, copyright is enforced as a civil matter, though some jurisdictions do apply criminal sanctions. Most jurisdictions recognize copyright limitations, giving users certain rights. Copyright came about with wider literacy. As a legal concept, its origins in Britain were from a reaction at the beginning of the 18th century. Copyright laws allow products such as literary and artistic production, to be preferentially exploited and thus incentivized.Copyright – The Statute of Anne came into force in 1710.
2. Copyleft – Copyleft software licenses are considered protective, as contrasted with free software licenses. Copyleft can be used to maintain copyright conditions for works ranging from computer software, to documents, to art. In general, law is used by an author to prohibit recipients from reproducing, adapting, or distributing copies of their work. Copyleft licenses for software require that information necessary for modifying the work must be made available to recipients of the binaries. The code files will usually contain a copy of the license terms and acknowledge the authors. Copyleft type licenses are a use of existing copyright law to ensure a work remains freely available. A non-profit organization founded by Lawrence Lessig, provides a similar license provision condition called share-alike. Copyleft is a copyright scheme in which an author surrenders some, but not all, rights under copyright law. Under copyleft, derived works may be produced provided they are released under the compatible scheme. Any modifications one makes public must be released under similar terms. For this reason some copyleft licenses are also known as reciprocal licenses, they have also been described to their self-perpetuating terms. Under fair use, however, the license may be superseded, just like regular copyrights. Therefore, any person utilizing a copyleft-licensed source for their own work is free to choose any other license provided they meet the fair standard. According to Free Software Foundation engineer David Turner, the term viral license creates a misunderstanding and a fear of using copylefted free software. It spreads like a plant, not like a virus."Copyleft – Copyleft symbol
3. Wikipedia community – The Wikipedia community is the community of contributors to the online encyclopedia Wikipedia. Individual contributors are known as "Wikipedians". The Oxford English Dictionary added the word "Wikipedian" in August 2012. Almost all Wikipedians are volunteers. Studies of the size of the community of Wikipedia showed an exponential growth during the early years. In April 2008, lecturer Clay Shirky and computer scientist Martin Wattenberg estimated the total time spent creating Wikipedia at roughly 100 million hours. In November 2011, there were approximately million registered user accounts across all language editions, of which around 270,000 were "active". As of today, the English Wikipedia contains an unknown number of anonymous contributors. There are 127,176 active editors on the English project. Wikipedia editors continue to increase the number, quality of the articles. A fifth spend more than three hours a day. Various studies have been done to the motivations of Wikipedia contributors. A paper written in 2005, called "Why Do People Write for Wikipedia? Incentives to Contribute to Open-Content Publishing", discussed the possible motivations of Wikipedia contributors. Oded Nov, in his 2007 paper "What Motivates Wikipedians", related the motivations of volunteers in general to the motivations of people who contribute to Wikipedia.Wikipedia community – Wikimania 2012 group photograph
4. Wiki markup – Its purpose is to be converted by wiki software into HTML, which, in turn, is served to web browsers. It was created on the original wiki site, WikiWikiWeb. There is commonly accepted standard language. Justification, keywords and so on depend on the particular wiki software used on the particular website. Different Wiki programs may support use of different sets of HTML elements within wikitext. In some cases, permitted HTML elements may be configured by individual wiki sites. MediaWiki supports many common HTML tags. There are different syntax conventions for these links. Many wikis, especially the earlier ones, used CamelCase to mark words that should be automatically linked. In MediaWiki, this convention was replaced with the notation, which Wikipedia calls "free links". Creole is an effort for a "common language to be used across different Wikis". There are several wiki engines that have implemented Creole. Version 1.0 of the specification was released in July 2007. It is not supported by MediaWiki. VisualEditor is an alternative to editing the raw wiki markup code.Wiki markup – Screenshot of the edit window in a Wikipedia article. Note the <nowiki> tag, used to escape wiki markup and HTML. HTML comments can be seen inside the <!-- --> tags.