Working With MediaWiki

runs on to be MediaWiki. Thankfully, MediaWiki is a popular wiki engine for wiki farms — in fact, it appears to be easily the most popular, with at least five serious wiki farms that use it. By comparison, most other wiki engines power no more than one.
    The biggest MediaWiki-based wiki farm, by far, is Wikia, at wikia.com. In fact, it’s the most popular wiki farm of any kind; according to the Alexa traffic-monitoring service, it’s currently among the top 200 most popular websites in the world, and among the top 100 in the United States. And that may be even understating its popularity, since some of its most popular wikis, like Memory Alpha (for Star Trek) and WoWWiki (for the video game World of Warcraft) have their own domains, which means that Alexa isn’t counting them as part of Wikia’s traffic.
    Wikia was founded in 2004 by Jimmy Wales — the co-founder of Wikipedia — as well as Angela Beesley (now Angela Beesley Starling), who was a Wikimedia Foundation board member at the time. For that reason, some people think Wikia is affiliated with Wikimedia or Wikipedia, but in fact there’s no official connection.
    Wikia differs from most other wiki farms in that they have to approve every new wiki that is proposed, with the main criterion being whether this new wiki will get sufficient traffic (Wikia currently gets all their revenue from the ads they run on the pages). So a wiki meant for use only by a specific group or organization wouldn’t be accepted, and a private wiki wouldn’t even be possible — all Wikia wikis are public. In practice, most wikis on Wikia — and certainly most of the popular ones — are on pop-culture topics: TV shows, movies, video games and books, with a special focus on anything related to science fiction or fantasy. If the wiki you’re considering creating is anything along these lines, Wikia is a very reasonable choice.
    Other wiki farms tend to allow anyone to create a wiki, with each wiki getting either a subdomain of the wiki farm’s main domain, or a directory. In some cases, wiki farms make their money from ads, while in others, they get money from customers who pay for extra service.
    The MediaWiki-based wiki farm closest to my heart is Referata, at referata.com — that’s because I created it and still run it, via WikiWorks. Referata has been around since 2008; it exists in order to provide hosting of a specific set of MediaWiki extensions based around Semantic MediaWiki — which you’ll be hearing much more about later in the book. To its credit, Wikia also provides support for Semantic MediaWiki, and in fact was doing so even before Referata existed — but it doesn’t allow the creation of arbitrary wikis; and Referata includes many more of the extensions based around SMW than Wikia does. Lest this get too technical, we’ll just say that, if you want a full set of features around Semantic MediaWiki, and/or you don’t think your wiki could get accepted on Wikia, Referata is a good choice. And even if you don’t want to use Semantic MediaWiki, Referata is still a reasonable option — most of the wikis on Referata, for better or worse, actually don’t use SMW. It offers a standard usage of MediaWiki for free, with some options -- like making one’s wiki private — requiring a monthly payment.
    Wikkii (wikkii.com and wikkii.net) is another interesting host — wikkii.com offers standard hosting, while wikkii.net allows administrators to install any custom extensions and skins that they want. Both are free.
    Other long-running MediaWiki-based wiki farms are EditThis.info (editthis.info) and Wiki Site (www.wiki-site.com).
    How to choose one of these? For simple wikis, it shouldn’t really matter. But if you have the need for special features, you can try looking at the site’s "Special:Version" page, to see what version of MediaWiki it’s running, and what extensions it has installed. You can also look at any of the wikis already hosted on that farm (usually there are a few linked from the homepage), to see what they look like, whether they’re inundated with spam (you can check Special:RecentChanges for that), how quickly they load, whether they have a distracting amount of ads, etc.

Download
    There are essentially two ways to download MediaWiki: as a “tarball”, or a single archive file, and via Git, a version-control system. Using Git is the recommended method, because it’s easier to install, and it lets you upgrade your code much more