Using a variety of APIs (Yahoo term Extractor and Alchemy are currently supported), semantic_extraction can automatically return a collection of keywords for an arbitrary block of text. If using Alchemy, it can also return named entities.

This gem auto-generates ExtJS compatible model specifications from your ORM (eg: ActiveRecord, DataMapper, MongoMapper)

Communicate easily with Shopify.com's Restful API.

Simple multi-agent framework. It uses AMQP for it's messaging layer.

StompBox - Git-based deployment console for TorqueBox

A DataMapper adapter for System Shepherd flavored REST services

Ruby API for Accessing the Freebase

Simple node and visitor definitions for Treetop grammars.

Path abstraction that provides easier interaction with paths and corresponding URLs.

Cinder does the heavy lifting for building and distributing iOS applications in a continuous integration environment.

Light wrapper for Google Ajax Feed API

Adds colors to Extlib logger

The Google API Ruby Client makes it trivial to discover and access supported APIs.

CouchDB Adapter for DataMapper

DataMapper's Query Tracker; She is super thorough and easy as hell, just the way you like it.

Cool additional hooks for DM Cutie.

An interface to DM Cutie repos.

Delated_job (or DJ) encapsulates the common pattern of asynchronously executing longer tasks in the background. It is port to DataMapper of direct extraction from Shopify where the job table is responsible for a multitude of core tasks.

DataMapper plugin that helps you manipulate an existing database. It creates mappings between existing columns and model's properties.

Ken Robertson's dm-paperclip with patches for rails > 3.0.0