The big RPG wikis I can think of are Forgotten Realms Wiki, The Great Library of Greyhawk (aka GLoG), Dragonlance Lexicon and PathfinderWiki.
There is also Mistipedia and Spelljammer Wiki (the last of which was founded by me).
Has anyone in the fan community ever discussed setting up a Midgard Wiki? I'm trying to learn about the setting and being able to navigate around a hyperlinked encyclopedia would be really useful.
Obviously there is a line between "writing about Midgard" and copyright infringement, so you couldn't just have editors signing up to a wiki and then copying and pasting text from PDFs wholesale, as that might lead to some gamers avoiding buying books from Kobold Press (instead of using a wiki to enhance their books, like I do with those other wikis). But PathfinderWiki works hard to wikify the Pathfinder Campaign Setting, without removing the need to buy the books to play the game, so I'm guessing some sort of discussion with Kobold Press would help sort out an editing policy they are happy with. (Paizo are so happy with the work of PathfinderWiki that they even sponsored an "editing contest" where the editor who updated the largest number of pages in a fixed period won some free Paizo stuff, so I think that shows that wikis can be good for business, if done well.)
BTW: Even though Forgotten Realms Wiki and Spelljammer Wiki are on Wikia (which is a wiki farm) I would strongly advise against someone jumping in and using their free hosting service to set up a Midgard Wiki without discussing this idea with other fans or Kobold Press first, as there are a couple of disadvantages to Wikia.
- Firstly Wikia earns money from wikis. Wikia is a bit of a Hotel California organisation, as they dump adverts on wiki pages and earn money from them. PathfinderWiki migrated onto Wikia ages back, and when they decided to leave, Wikia retained a copy of their wiki, creating a rival Pathfinder wiki, instead of allowing them to remove their content. (Wikia had another large battle with Wowpedia - the wiki of the World of Warcraft, and even claimed ownership of their original name and logo when they left. )
- Secondly Wikia has licensing that I'm not happy with. An unethical Print on Demand book publisher has misused the licence on both those wikis to publish fake FR and SJ books stuffed with random articles. That's not fair to fans. If anyone is interested in this, then a wiki hosted by a Midgard fansite would allow for better licensing (non-commercial reuse only).