We all know about Wikipedia, that vast storehouse of online knowledge that is also the poster child for sometimes inaccurate data. Why do people say you can't trust it? Because it's a wiki.
A wiki comes from the Hawaiian word for "quick" and, as Wikipedia defines it, a wiki is "a website whose users can add, modify, or delete its content via a web browser using a simplified markup language or a rich-text editor." That means it's created by both experts and amateurs, but it also means it has the knowledge and input of literally thousands of contributors.
If you've only ever heard the term "wiki" in regards to Wikipedia, you're missing out. There are thousands of them online with some very specialised content – just look at the list at WikiIndex, a wiki about wikis. For example, the Wikimedia Foundation that keeps Wikipedia going also supports a dictionary called Wiktionary, a quote collection called Wikiquote, and a free news source called Wikinews, among others. Specialised wikis cover Star Trek (Memory Alpha), Star Wars (Wookieepedia), and pretty much everything else you can think of from Muppets to music lyrics. These things are everywhere.
But wikis don't have to be limited to giant websites full of user-generated content. Many companies use a wiki to facilitate tech support, for example. It's like a user discussion forum, but better written (in theory) and better organised. In fact, you can personally put a wiki to work very easily, either for use by a group, you alone, or the entire Internet. The number of tools for creating a wiki almost rivals the number of wikis already created. Many have blossomed from old school wiki software into full-blown corporate collaboration tools (like PBWorks) or into user-content driven sites (check out Wetpaint).
We'll show you some of the tools you can use to create a wiki that's strictly personal and only accessible by you, or a collaborative wiki you either host on your own site or someone else's, open to contributions from all.
First, a word about how wikis work and what you need to know to even write in one; this could be the stumbling block that keeps you away from the ways of the wiki.
Because you typically use a web browser to do your writing inside a wiki, you're not always going to get a WYSIWYG (what you see is what you get) interface. In trying to make wikis usable by anyone, from the highest tech to the lowest, a syntax was created for marking up text. It's done in a way anyone can handle with any text editor, so the output is always the same. This includes methods for creating headlines, subsection headers, links, horizontal lines, making lists, using bold and italics, and more. It's not even like HTML. It's called wiki markup and, to be honest, if you're new to using a wiki, it'll mean a whole new way of writing.
Wikipedia's own help entry on wiki markup covers it pretty well. For example, linking within a wiki can be pretty simple; put double square brackets around a term like [[Manual of Style]] and that text turns into a link to that page on Wikipedia (if you're putting the link on an internal Wikipedia page). There's no room for error because if you get the name wrong, it won't see the matching page, so there’ll be no link. More precisely, you'll create a link to an empty page.
If you want to use different text for the link itself, use a pipe character between the link text and the target. So [[public transport|transportation]] would show the latter, but link to the former within the wiki. But you don't need the pipe for a link to an external link: [http://www.itproportal.com ITProPortal] (with single square brackets) would make the link to ITProPortal.
I won't go too in-depth with this because the rules above apply specifically to Mediawiki, the software that runs the sites of the Wikimedia Foundation (see below). Other sites and software can vary. Be aware as you’re going into this that you may indeed be learning an entirely new syntax for communication, one that might not be worth taking the time to master if your wiki is personal or for a very small group.
By definition, any wiki software you run that's only on your computer is going to be personal. Not that you can't share your PC, but most of these solutions are meant to be simple engines for note-taking.
TiddlyWiki: Imagine a wiki that is one giant document. However, the sections are easily accessed not by scrolling but by instantly linking among the areas. In this case, those sections are called "tiddlers," which leads to the name TiddlyWiki. It's essentially an HTML document you can edit from within the browser, then use your browser to access it anytime you want, jumping from tiddler to tiddler as needed. If you put the TiddlyWiki file on a web page you own, anyone can edit it, giving you some instant group wiki action if needed. If you want a version of TiddlyWiki that's already hosted online, TiddlySpace will provide it, though you will need to know some wiki markup to put either of them to use.
Zim Wiki: This software isn't just for Windows. Linux users may need wikis more than anyone, and this tool lets a user start making notes instantly, creating new pages on the fly with "WikiWords" and some WYSIWYG tools. The Windows-only Linked Notes looks very similar. Both also have portable installers, so you can run them from a USB flash drive and take it anywhere.
Notational Velocity: This free, open source, Mac-only note taker is for gear heads who never take their fingers off the keyboard. In fact, its sparse interface doesn't seem particularly Mac-esque. It's all about taking quick notes and quickly finding them again.
A note about the installable tools above: If you use multiple computers but still want access to this data on all systems, a sync tool like Dropbox will easily make that happen in most cases.
If you think a wiki sounds like a great solution for you to write a personal, private journal, well, it can be – but be careful. These tools are all geared towards the sharing, not the keeping of secrets. You'll want to put the data some place extra safe from prying eyes. If you can't wait to write "Dear Diary" however, there's a great online journal site that prides itself on privacy called Penzu.
Hosted on the web
If you don't want the hassle of downloading and/or installing a wiki, your best bet is to use a tool that is already hosted on a website. You won't always get the option of personalising it for your domain name (at least not without paying for it) but you will get the benefit of a quick start to your wiki-ing.
Wikispaces: Arguably the best stop for either a personal or a group wiki that's affordable (usually free, but extra features will cost you) and easy (they promise no learning curve), Wikispaces allows one-click editing of any page in your wiki using WYSIWYG in-browser tools. The biggest limit is size – there’s only 500MB of space with the free option, which can be gobbled up fast since Wikispaces also supports video and graphics uploads. If you want more space, you’ll have to subscribe.
Wikia: If you're prepared to start a public wiki right now on any fun topic, especially about gaming, entertainment, or lifestyles, your fastest start will probably come at Wikia. Well, once the wiki topic is approved, that is; Wikia is running a business and doesn't let just anything go. That said, it passed 100,000 wikis almost two years ago, and is still going strong by throwing ads on each wiki. It's the home of wikis like Memory Alpha, Wookieepedia, and others that cover topics like Harry Potter, Glee, Batman, Skyrim, crafts, Lady Gaga, highway rest stops. The list is endless. And you can add to it.
Google Sites: This service of Google is not really a wiki; it's a web page creation tool based on a former wiki tool called JotSpot. Luckily there's still a template within Google Sites called “Project Wiki” that you can use to start something that’s a close approximation. Click the Create button on the site, then click "Browse the gallery for more" and you'll find it. Sharing the site with others opens it up to collaboration in true wiki fashion.
Hosted on your website
If you've got some web know-how and want more control over your wiki, these server installable software packages are what you need.
MediaWiki: There's no doubt this is the flagship of wiki products; it was created by the Wikimedia Foundation to be the basis for all its tools, including Wikipedia. Its price (free) and ubiquity means that many web host companies have pre-installed it. If they haven't, you'll need to download and install it, which will require some web publishing expertise with FTP and databases. It's really made for big projects that expect to get millions of hits per day, so think carefully about whether or not it's overkill for you. Your wiki on the different kinds of potholes in your city may not end up generating Wikipedia-style levels of traffic.
Tiki Wiki CMS Groupware: Totally free and no harder to install than a blog tool like WordPress (again, you'll need some web publishing chops), Tiki Wiki is especially good for businesses. The admin tools are extensive and the abilities of the software go beyond just wiki pages; Tiki Wiki is also a publishing tool for blogs and articles, and can be used for tasks like project management. It even integrates with social networks like Facebook and Twitter. Collaboration is its strength – running on fast enough hardware, it will keep users sharing and working for a long time.
Interlinks: Limited to those who do have WordPress installed, this add-on for the blog platform does one thing: It lets you use wiki markup-style tags with the square brackets to make links in your current post to other posts.