A simple, Git-powered wiki with a sweet API and local frontend.
A quick & dirty git-powered Sinatra wiki
Irwi is Ruby on Rails plugin which adds wiki functionality to your application.
Olelo is a git-based wiki which supports many markup languages, tags, embedded TeX and much more. It can be extended through plugins.
The easy to use rails wiki
A personal and collaborative wiki for Vim users
include Gollum into Rails with ease
A no-frills Merb wiki extracted from wiki.merbivore.com
An elegant wiki system for anyone who respects their grandmother
A small blog + wiki engine built on Sinatra + Stone
a sinatra/couchdb wiki
a simple wiki powered by sinatra
Wiki for Ramaze running on Innate
A Rails powered wiki with a sensible code base. Work in progress.
Gitki is a wiki using git to store data.
Wiki engine based on Rails 3 engine
Instiki is a Wiki Clone written in Ruby that ships with an embedded webserver. You can setup up an Instiki in just a few steps. Possibly the simplest wiki setup ever.