CommunityEngine is a free, open-source social network platform for Ruby on Rails applications. Drop it into your new or existing application, and you’ll instantly have all the features of a basic community site.

A limited command line interface to Facebook

facy: first colorful terminal client for facebook

Posting to the most popular social media

A broadcasting microframework making publishing of messages to different services easy

A mobile web application framework in Ruby

New Instagram Graph API

Gem that focus on making a public site's resources very quickly while being very configurable!, supports facebook sharing, instagram and google analytics integration

Authlogic extension to support Facebook OAuth2 javascript sessions. Currently requires koala but is easily extended for other facebook api wrappers.

Eukaliptus is a set of helpers and bug fixes for browsers to help you build Facebook iframe applications or user fan tabs.

Facebook integration for Rack & Rails application

Installer and helpers for using Koala with Rails 3

Social Media allows publishing to any number of social media services using one common API.

Crawls congressional websites for press releases.

#Crowdsourcing management system for #RubyOnRails: http://bit.ly/voluntary-0-7-1

Uses Ajar's API to insert public URIs in place of local APIs for Facebook Open Graph connections.

Get business ratings.

BlueVelvet connects to a Facebook page and returns content from it in partials that can be modified by the developer.

Contentful Social Publishing Gem

Easy FB custom audience creation