This is simply the best CMS in town. User authentication, widgets, slideshows, easy UI with drag and drop, publishing system, versioning, etc.

Manage your geoserver configuration like you manage your database: with migrations

Makes using latitudes and longitudes on forms easier.

Rails On Rails engine to import and generate currency rates

Full support for the Rails 3.1 asset pipeline when testing your coffeescript or javascript files using Gerbil

Rails based CMS

Gerillass is an open-source toolkit that contains a set of Sass mixins to help designers and developers to create better, faster and consistent user interfaces.

Localization support for Ruby on Rails(>=2.3.2) by Ruby-GetText-Package.

Inspects models and other modules to easily generate .po-files and translate them with POEdit.

Getty connect gem

A Guilded component for the Fancybox JavaScript library that makes Rails development with Fancybox a breeze.

a gtk+ based grid data analyser and viewer writen on Ruby

A Guilded component that displays Rails flash messages in an interface similar to OS/X's growler.

A Rails Guilded component that will disable form elements once the submit button has been used.

Admin-namespaced scaffold generator

declarative_authorization is a Rails plugin for authorization based on readable authorization rules.

Using phantomjs to pre-run javascript in emails. This is best if you have content that uses mustache templates that you would like to reuse in your emails.

Abukuma compatible styles for kaminari gem.

Based on Suspenders from thoughtbot, Gimbal is a base Rails project I use to streamline the beginning of my Rails projects.

A Rails engine that handles credit cards for Authorize.net and Braintree using ActiveMerchant