Fandom - The entertainment site where fans come first.
TiddlyWiki - a non-linear personal web notebook
Miraheze - Miraheze is a wiki farm (hosts wikis) for free and with no ads, it also provides custom domains...
Zim Wiki - Zim is a graphical text editor used to maintain a collection of wiki pages. Each page can contain links to other pages, simple formatting and images.
Wikiful - Wikiful is an online platform that makes it easy to build and share a wiki.
ZuluPad - ZuluPad is a notepad on crack.