Radlibs requires a few things to get started, first of all it needs at least Couchbase 1.8.x, which you can download here: Couchbase Server Download.
The Couchbase Ruby Gem requires the libcouchbase c library native extensions before you install the gem. Installation instructions for various systems can be found here: Couchbase Ruby Gem
Copy or rename /config/yetting.dist.yml to /config/yetting.yml
You need to create a Facebook application in order to enable social login to work (which is the only type of login currently configured). To do this, log into your Facebook account and go here: Facebook Developer Center You will need to copy your Facebook App Key and Facebook App Secret Key to the /config/yetting.yml file. In addition if you want it to work on localhost, the easiest way to do this is to setup a subdomain DNS entry that points to 127.0.0.1 like: radlibs.domain.com A 127.0.0.1, then put that domain in your Facebook App config for Site Domain(s) and Website with Facebook Login Site URL. Your site and the Facebook settings must match for Social Login to work properly and callbacks to execute.
In order for word lookups to work you need to go to Wordnik Developers and sign up for an API key, you will need to copy the API key, your username and password to /config/initializers/wordnik.rb