Robokassa is payment system, that provides a single simple interface for payment systems popular in Russia. If you have customers in Russia you can use the gem. The first thing about this gem, is that it was oribinally designed for spree commerce. So keep it in mind.

RubiGen - Ruby Generator Framework

A simple to use, yet powerful Ruby framework for building console-based applications.

Data mining and machine learning algorithms for JRuby

This is a Ruby API for Fitbit.com, currently scraping, but soon will use the officail API (when released)

ScheduleFu allows scheduling events with dates and times. It includes both the model and view portions of a calendar. It borrow heavily from acts_as_calendar (http://github.com/dball/acts_as_calendar) and calendar_helper (http://github.com/topfunky/calendar_helper).

Serious is a simple, file-driven blog engine inspired by toto and driven by sinatra with an emphasis on easy setup

Integrate SimpleCov results into Atlassian Bamboo CI server

A library for using Notifo. Notifo is a way for users to receive mobile notifications for anything, more at http://notifo.com. This gem uses John Nunemaker's awesome HTTParty.

SocialPoster is a gem that allows you easily post to different social networks.

Spree Redirects adds an interface for redirecting old url's to new ones.

Tiny IRC Bot Frameowkr

Tickle is a date/time helper gem to help parse natural language into a recurring pattern. Tickle is designed to be a compliment of Chronic and can interpret things such as "every 2 days, every Sunday, Sundays, Weekly, etc.

whmcs-ruby: Ruby bindings for the WHMCS API

A simple ruby API wrapper for interacting with the Wunderground API

This is taken from XMLCanonicalizer/WSS4R and http://github.com/borisnadion/xml-canonicalizer

A complete Ruby API for handling SMS messages via 4info.com

Act-as-Buddy is a gem to allow any model to implement self relation. For eg: the friendships of a user can be implemented easily by self relation technique of act_as_buddy. Any Model can be buddied or lopped on to itself. Main uses would be for Users create friends etc.. Eg: User has many friends...

You can use active_cart as the basis of a shopping cart system. It's not a shopping cart application - it's a shopping cart framework.

You want to batch create/destroy/update many records at once with activescaffold?