There are many ways to arrange online collaboration, but probably the most deceptively simple is Wiki. It’s so simple that those who see it for the first time often find it trivial and uninteresting. Yet it’s this very simplicity that makes Wiki attractive as an unobtrusive tool for personal note taking, as well as for collaboration. Wiki is a client-server tool, seemingly just another Web server, but with a twist: It is totally open. Furthermore, it uses the existing Web infrastructure, and anyone who has a stock Web browser can play.
In our book, The Wiki Way (Addison-Wesley, March 2001), the author and Ward Cunningham, Wiki’s creator, tried to document and introduce the concept to a broader audience, and additionally provided a new stand-alone version of the Perl source to make an "instant serve" solution possible for the reader. A further aim is to examine many of the implications of this kind of open collaboration, and present user stories to shed further light on practical implementation.
Ward Cunningham, Wiki’s creator, called Wiki "the simplest online database that could possibly work". In 1994, he wanted a quick way to collaboratively publish software patterns on the Web. Ideas that had developed from his work with program development and HyperCard stacks went into it, and the first "Wiki server" was born.
Wiki content is easy and quick to edit, thus inviting user contributions. In addition, if you follow Wiki naming conventions, pages automatically and elegantly interlink with each other in meaningful ways. Related content is "only a click away". Wiki is unusual among group communication mechanisms in that it allows the organization of contributions to be edited in addition to--and actually as part of--the content itself.
The crucial and characteristic features of Wiki are the following:
Open co-authoring of text. Anyone in the world can change anything (or change it back) by just following the edit link on any page.
Transparent hyperlink mechanism for linking content. Instant and automatic cross-linking with no broken links.
Seamless integration with Internet URL hyperlinks. Just type in the full URL in the text, and Wiki automatically renders it as an active hyperlink.
At the functional level (that is, the user experience), the essence of Wiki can be summarized by these statements:
Wiki invites all users to edit any page or to create new pages within the Wiki Web site, using only a plain-vanilla Web browser without any extra plug-in or add-on.
Wiki promotes meaningful topic associations between different pages by making page-link creation almost intuitively easy, and by showing whether an intended target page exists or not.
Wiki is not a carefully crafted site for casual visitors. Instead, it seeks to involve the visitor in an ongoing process of creation and collaboration that constantly changes the Web site landscape.
Wiki is a lot about a collaboration space, albeit an unusual one because of its total freedom, ease of access and use, simple and uniform navigational conventions, and apparent lack of formal structure. It is also a way to organize and cross-link knowledge; perhaps the main purpose for the single-user Wiki.
Some spin-off effects are the following:
Many mutable entry points, including a history-of-changes list
Flexible restructuring of page cross-links to reflect new relationships
Multi-threaded, nonlinear discussions
Ease of writing, ease of collaboration
Wiki supports some basic structural markup, but according to the less-is-more philosophy. Therefore, it uses simple text patterns rather than explicit HTML tags. The point is to encourage visitors to contribute content without having them worry unduly about markup. What markup there is follows a simple textual syntax, often close to established plain-text conventions. Any given wiki might have more or less markup options with varying syntax, and one of the aims of the book was to discuss and perhaps contribute to a unified basic markup syntax for wiki servers. (Note that we use capitalized "Wiki" to mean the concept, while "wiki" stands for a practical implementation.)
For example, to make a list, the formal syntax set out by the authors is to start each bullet item with a star "*", or a pound "#" for a numbered list. Often, however, a wiki is coded to quietly accept other common conventions as well, such as a number followed by a period. This is much easier than manually keeping track of normal HTML <ol> <li> </li> <li> </li> </ol> nesting. Special client software could make such specific markup transparent, but then the feature of using an unmodified Web browser would be lost.
Wiki can be used in many ways, and frankly, we’re constantly discovering new uses for the tool and new ways to tweak or add functionality. In general, applications can be sorted as single-user or multi-user. On the other hand, there is some overlap, and what starts off in a single-user context can easily end up in a multi-user one.