FeedsActiveRecord Default Values
default_value_for and active_record_defaults
ActiveRecord Encryption
attr_encrypted, strongbox, sentry, Lockbox, lucifer, and more
ActiveRecord Enumerations
enumerated_attribute, enumerate_by, enumerate_it, and more
ActiveRecord Index Assist
rails_indexes and ambitious_query_indexer
ActiveRecord Named Scopes
searchlogic, pacecar, utility_scopes, can_search, and more
ActiveRecord Nesting
awesome_nested_set, ancestry, acts_as_tree, and more
ActiveRecord Sharding
data_fabric, db-charmer, octopus, and ShardTheLove
ActiveRecord Soft Delete
acts_as_paranoid, acts_as_archive, and more
ActiveRecord Sortables
acts_as_list and sortable
ActiveRecord User Stamping
acts_as_audited, user_stamp, userstamp, and more
ActiveRecord Value Cleanup
attribute_normalizer, strip_attributes, nilify_blanks, and more
ActiveRecord Versioning
acts_as_versioned, vestal_versions, paper_trail, and more
API Clients
twitter, fog, googlecharts, garb, twitter_oauth, and more
Asynchronous HTTP
eventmachine and rev
Backups
safe, backup, backup_fu, and db2s3
Browser testing
webrat, capybara, culerity, watir, celerity, and more
Calendars
event_calendar, calendar_helper, later_dude, and more
Code Metrics
metric_fu, rails_best_practices, rcov, reek, roodi, and more
Content Management
radiant, refinerycms, browsercms, typo, adva_cms, and nesta
Continuous Integration
cijoe, integrity, cruisecontrol.rb, signal, cap_gun, and more
Continuous Testing
watchr and zentest
CouchDB Clients
couchrest, couch_potato, couch_foo, couchrest-rails, and more
CRM Apps
fat_free_crm, mongo_crm, forgetmenot, and cohort
CSS Frameworks
blueprint-css, compass, oocss, fluid960gs, and more
CSS with Ruby
less, deadweight, css_dryer, sass, and stylish
Daemonizing
daemon-kit, robustthread, daemon_generator, and more
Daemon Management
daemon_controller and daemon-spawn
Dependency Management
bundler, braid, piston, giternal, isolate, and more
Deployment Automation
moonshine, capistrano, rubber, inploy, vlad, and phd
Distributed Testing
parallel_tests, spork, hydra, testjour, deep-test, and more
Documentation Tools
yard, sdoc, hanna, ajax-rdoc, erbook, and ron
E-Commerce
spree, active_merchant, invoicing, shippinglogic, and more
E-Mail Processing 
mailman, fetcher, and mail_fetcher
E-Mail Sending
mail, pony, tmail, resque_mailer, mail_queue, and popthis
Exception Notification
exception_notification, hoptoad_notifier, and more
Forum Systems
altered_beast and rboard
Game libraries
rubygame, gosu, chingu, gamebox, flonkerton, and jemini
Gem Creation
jeweler, newgem, bones, echoe, hoe, and inochi
Gem Doc Viewers
bdoc, gembox, sinatra-rubygems, and docbox
Geocoding & Maps
geokit-gem, geokit-rails, graticule, acts_as_geocodable, and more
Graphing
open_flash_chart, gruff, lazy_high_charts, seer, and more
HTML parsing
nokogiri, hpricot, scrubyt, scrapi, and libxml-ruby
HTTP clients
httparty, typhoeus, mechanize, em-http-request, and more
I18n
globalize2, i18n, translate_routes, r18n, fast_gettext, and more
Image Processing
mini_magick, image_science, devil, and im_magick
irb Tools
dotfiles, awesome_print, hirb, racksh, looksee, and bond
IRC Bots
autumn, isaac, rbot, cinch, summer, and sprinkles
JavaScript Frameworks
jquery, scriptaculous, prototype, mootools-core, yui3, and more
JavaScript Testing
blue-ridge, testswarm, jspec, screw-unit, hanoi, and more
JavaScript Tools
sprockets, juicer, jabs, frontcompiler, packr, and jake
LDAP
authlogic_ldap, ruby-net-ldap, and more
Markup processors
rdiscount, redcloth, bluecloth, kramdown, rpeg-markdown, and more
Microformats
mofo, microformats_helper, prism, and assert-microformats
Mocking
rr, mocha, stump, flexmock, and facon
Mocking Web Requests
fakeweb, webmock, artifice, vcr, netrecorder, and more
Music & MIDI
archaeopteryx, midiator, jazztoolbox, and more
Packaging Systems
rip, rpg, coral, spoke, and ruby-which
Packaging to Executables
ocra, crate, and rubyscript2exe
PDF Generation
prawn, PDFKit, prawnto, wicked_pdf, wkhtmltopdf, and more
Presentation Software
showoff, slidedown, jQuery-Presentation, s6, and slideshow
Project Management
redmine, retrospectiva, oupsnow, radtrack-core, and teambox
Prototype Replacements
jrails, jquery-ui-rails-helpers, right-rails, and more
Queueing
resque, delayed_job, amqp, workling, cloud-crowd, and more
Rails Admin Interfaces
active_scaffold, typus, admin_data, streamlined, and more
Rails App Templates
rails-templates, suspenders, BigOldRailsTemplate, and more
Rails Asset Management
asset_packager, jammit, smurf, bundle-fu, rucksack, and more
Rails Authentication
authlogic, restful-authentication, devise, clearance, and more
Rails Authorization
cancan, declarative_authorization, acl9, and more
Rails Captcha
recaptcha, negative-captcha, brain_buster, captcha, and more
Rails Comments
acts_as_commentable, disqus, and more
Rails Controller Abstractions
inherited_resources, resource_controller, and more
Rails DB Bootstrapping
seed-fu, populator, bootstrapper, db-populate, and more
Rails File Uploads
paperclip, attachment_fu, carrierwave, dragonfly, and more
Rails Fixture Replacement
factory_girl, machinist, object_daddy, dataset, and more
Rails Form Builders
formtastic, semantic_form_builder, and more
Rails In-Place Editing
in_place_editing, rest_in_place, jintastic, and more
Rails Instrumentation
rails-footnotes, rpm, rails_metrics, rackamole, and more
Rails Menu Builders
simple-navigation, semantic-menu, simple_navigation, and more
Rails Pagination
will_paginate, paged_scopes, sort_by, and has_paginate
Rails Permalinks & Slugs
friendly_id, permalink_fu, stringex, find_by_param, and more
Rails Presenters
active_presenter, apotomo, and viewtastic
Rails Ratings
ajaxful-rating, acts_as_rateable, is_rateable, and more
Rails Search
thinking-sphinx, sunspot, acts_as_ferret, ferret, rsolr, and more
Rails Subdomains
subdomain-fu, subdomain_routes, subdomain_account, and more
Rails Tagging
acts-as-taggable-on, is_taggable, and more
Rails Wizards
actsaswizard, wizardly, wizard, and partially_valid
Random Data Generation
forgery, randexp, faker, and random_data
Recurring Events
ice_cube, recurrence, tickle, runt, schedule_fu, and more
Reporting
statistics, dynamic_reports, ruport, odf-report, munger, and more
RSS Feed Parsing
feedzirra, feed-normalizer, simple-rss, feed_me, and more
Ruby Version Management
rvm, pik, rvm.el, and which_ruby
Scheduling
whenever, rufus-scheduler, craken, and Taskit
Scripting Frameworks
thor, rake, boson, and sake
Security Tools
rails_xss, tarantula, loofah, xss_terminate, and more
Server Monitoring
god, visage, amnesia, and webstats
SOAP Clients
savon, handsoap, and serviceproxy
Social Network Builders
insoshi, communityengine, lovd-by-less, pfeed, and more
Spam Detection
rakismet, viking, defender, defensio-ruby, akismetor, and more
State Machines
aasm, state_machine, ruote, workflow, state-fu, and more
Static Website Generation
jekyll, toto, webby, staticmatic, nanoc, and bonsai
Syntax Highlighting
highlight, harsh, tm_syntax_highlighting, albino, and more
Systems Integration
chef, sprinkle, passenger-stack, puppet, babushka, and more
Template Languages
haml, mustache, liquid, erector, parkaby, and ruhl
Testing frameworks
cucumber, rspec, shoulda, steak, riot, and bacon
Text Editors in Ruby
redcar, diakonos, and arcadia
Time Warping
timecop, delorean, time-warp, and time-zone-warp
Visualizing Data
raphael and ruby-processing
Web App Frameworks
rails, sinatra, padrino-framework, merb-core, ramaze, and more
Web servers
passenger, thin, unicorn, mongrel, and ebb
Wiki Apps
git-wiki, instiki, signal-wiki, collective, perwikity, and more
XML Mapping
happymapper, roxml, sax-machine, and representative
