zammad
enterprise-ready helpdesk and customer support system
Active open-source Ruby on Rails apps
Hot off the push and API request, and probably some background jobs.
CQRS Demo Application
a Rails app using advanced DDD concepts
Notebook Gallery
enterprise Jupyter notebook sharing and collaboration platform
Discourse
next-generation discussion platform
Mastodon
distributed, interconnected microblogging
Hitobito
full-scale group hierarchy management
Open Build Service
build service for Linux packages
va.gov
API for va.gov
CrimeThinc.com
the app that powers this website
TalentProtocol.com
be your own NFT
GitLab
self hosted Git management
Decidim
a framework for democracy
World Cube Association
everything for the World Cube Association
Spree
a flexible e-commerce platform
Solidus
e-commerce system
RailsDevs.com
the RailsDevs.com board
OpenProject
project management system
whitehall
government content publishing for gov.uk
MarkUs
submission and grading for student assignments
WikiEduDashboard
course dashboard system
openstreetmap.org
crowd-sourced map of the world
vglist.co
video game library tracking
OpenFoodNetwork
software to manage the lifecycle of food
Growstuff
tool for small-scale food growers
Fat Free CRM
the original Rails-based CRM
Fat Free CRM
a clean, customizable CRM
Danbooru
taggable image board
24pullrequests
Give back to open-source
Octobox
GitHub notification manager
forem
the platform that powers dev.to
TheOdinProject.com
free web development courses
Chatwoot
customer engagement platform
Brainstormer.online
collaborative brainstorming
Organization for Transformative Works Archive
archives of fanworks, including fanfic, fanart, and fan vids
planningalerts.org.au
planning alerts for Australians
DCAF Case Management
case management system
iNaturalist.org
social network for nature stuff
huginn
open-source IFTTT
Autolab
course management and auto-grading of assignments
Violet
automation, CMS, blog, forum and email thing.
pinballmap.com
source code to pinballmap.com
rubygems.org
The Ruby community's gem hosting service
Spina
A beautiful CMS for Rails developers
Rescue
save cute cuddly puppies
Human Essentials
management system for essentials banks
Astuto
customer feedback tool
Blazer
dashboard for your database
Texterify.com
translation and localization management
icare
carpooling platform
visualizer.coffee
visualize hipster coffee machines
Convene
digital spaces
PG Hero
performance dashboard for PostgreSQL
TheyVoteForYou
Holding politicians accountable
Manage IQ
Automate, optimize, and control your cloud and virtualization services
E621.net
an art image board
consul
open government and participation software
libraries.io
open-source discovery service
lobsters
link-aggregation site, inspired by Hacker News
exercism.io
code practice and mentorship
TaxonWorks
workbench for biodiversity informatics
Alaveteli
easy FOIA requests for any jurisdiction
Pupilfirst
everything you need for an online school
CircuitVerse.org
circuit simulator
Skyderby
flight analysis and competition scoring
Open Split Time
endurance event data management
Loomio
make decisions together
Pay
payments engine
Coursemology
open-source gameified learning platform
Open-Source Event Manager
event management tool tailored to conferences
Listed.to
online publications with automatic newsletters
Klaxon
get emailed when a website changes
AgileVentures
source code to agileventures.org
Pageflow
multimedia storytelling
Clain for Crown Court Defense
advocacy for defense payments
FabManager
FabLab management tool
Ecosystem Dashboard
open-source ecosystem monitoring
OnRuby
whitelabel for ruby community management
Registry
TLD management software
OpenSourceRails.org
the codebase to this site
Alchemy CMS
popular content management engine
Bike Index
the internet's bike registry
fromthepage.com
crowdsource handwritten documents
Panoptes
API to support user-defined research projects
Feedbin
open-source feed reader for multiple platforms
Chaskiq
full-featured live chat, support, and marketing platform
Ekylibre
farm management information system
StockAid
manages inventory for the Grateful Garment Project
Black Candy
self-hosted music streaming server
sharetribe
Marketplace platform
PublicLab.org
collaborative knowledge-exchange platform
rubytoolbox.com
catalog of all Rubygems that keeps track of popularity and health metrics
Notebook.ai
structured writing tool
Hackershare
social bookmarking and knowledge-sharing
Annict.com
anime website
Motor Admin
if ActiveAdmin and Blazer had a baby
Homeland
homeland.ruby-china.org
Canvas LMS
enterprise-grade learning management system
weg.li
report bad german parkers
Tracks
software for implementing David Allen's Getting Things Done™ methodology
CSVLint.io
validate CSV files
Haven
self-hostable private blogging
Terrastories
geostorytelling
AirCasting
platform for gathering, visualization and sharing of environmental data
samson
Web interface for deployments
Postal
mail delivery platform for incoming and outgoing e-mail
Dog API
an API for doggo info
Ciao
uptime monitoring
Central
Fulcrum project planning tool fork
LumenDatabase
database of legal complaints and requests for removals
TimeOverflow
time banking system
Racing On Rails
bike racing association management
Caffeinate
a framework for easily creating and scheduling email campaigns
Expertiza
peer-reviews app, supported by the National Science Foundation
Punchclock
simple electronic punch clock
alonetone
home for musicians, their tracks and albums
if-me.org
mental health communication
Contributors
contributors.rubyonrails.org
ebwiki.org
database of police abuse cases against people of color
openSNP
annotate your SNP-set
Carto
location intelligence and data visualization
Upcase.com
learning platform for programming
Camaleon CMS
yet another content management system
CodeTriage
directory of open-source projects with open issues
nindika.com
nintendo switch e-shop
Calls For Proposal App
manage a conference CFP
kitsu
kitsu.io API server
FoodSoft
manage food coop
Concerto
digital signage system
HRMS
HR management
Podify
make podcasts from youtube-dl
Splits.io
speedrunning data and analysis
Coyote
image annotation
Calagator
community calendar platform
Gamocosm.com
Minecraft server hosting
sumofus.org
source code to sumofus.org
foreman
server lifecycle automation
Fae CMS
another CMS
Open Source Billing
Beautifully Simple Billing Software
RebelsManager
a platform for social good
getsiteinspector.com
a tool for developers to check their pages
Diaspora
community-run, distributed social-network
Outpost
service directories platform
ActiveWorkflow.org
turn complex requirements to workflows
Droptune
music notifications for Spotify and Apple Music
Morph.io
web scraping tool
Errbit
open source, self-hosted error catcher
Locomotive CMS
a multisite CMS with liquid templating
Coinfi
crypto market intelligence platform
LearnAwesome.org
social network of learners
Wreeto
note-taking, knowledge management, and wiki
Verboice
Toolkit for people who literally "need a voice"
dokno
Rails Engine for storing and managing an app's domain knowledge
Abalone
data tracking and analytics for conservation efforts
Huboard.com
better GitHub issues
RubyTogether.org
RubyTogether.org
Fulcrum
Original project planning
Refinery CMS
a modular and extendable CMS
Fairmondo
free market place in the hand of the users
Cuttlefish
a good-enough SMTP server so you can ditch SMTP providers
Diveboard
Diveboard.com
Action Center
EFF Action Center platform
Storytime
another CMS
Airesis
eDemocracy
Peatio
crypto currency exchange software
Envizon
network visualization and pentest reporting
Covidlist
connect vaccinations with those who need to be vaccinated
Redmine
web based project management
HellRaiser
vulnerability scanner
Drug Gene Interaction Database
The Genome Institute's drug gene interaction database
Barong
auth server
Plylst
Spotify playlist tool
Datoji
easy JSON mocking for developers
Hound
Your code, always in style.
FeedBunch
simple and elegant reader
Helpy
A Modern Helpdesk Alternative
Hackathon Manager
hackathon registration and logistics
Trailmix
A place to write.
Staytus
status pages
GitReports.com
allow anonymous users to submit bugs to GitHub repos
Orientation.io
Wage war against outdated documentation
Ghostlight Folio
theatrical production management
CodeCuriosity.org
platform to reward OSS contributors
OpenFarm
open database for farming and gardening knowledge
Workarea
enterprise-grade commerce platform
Bluedoc
document management tool
ShinyCMS
plugin-based CMS
Pokr
agile estimating and planning
Simple Discussion
simple and extensible Rails forum
Vinifera
tool to monitor leaked secrets
CaseIn
CMS toolkit
HyperCable
analytics
Radiant CMS
No-frills CMS
brief-ideas
journal for brief ideas
EasyRaceLapTimer
open-source IR lap time tracker
tip4commit.com
reward contributors
datorss.com
RSS search
OneBody
church management software
Pig CI
Rails performance monitoring, plus CI
nokul
solution for universities to manage all the complex procedures of a university online
Amahi
your personal cloud and media server
FederalRegister.gov
daily journal for the United States Government
Juvia
commenting server of the likes of Discus or IntenseDebate
Catarse
open-source crowdfunding platform
AppPerf
application and performance monitoring tool
Gwaphics
graphic design tool
LocalOrbit
local food management stuff
Reservations
equipment loans and reservations software
Sanataro
household accounting software
Coderwall
Professional network for software engineers
Hours
Time registration that doesn't suck.
Recipy.fr
defunct website of a recipe site
Comfortable Mexican Sofa
a lovely-named CMS
Lale Help
collaborative platform for refugee support
Email Dashboard
email suite for marketing and CRM
Classroom
automates repository creation and access control for teachers
TagTeam
social tagging for academics
BareMetrics.com
v1 of baremtrics.com
Duckrails
tool to mock API endpoints
Binda CMS
headless CMS
Mission of Mercy
management of free dental clinics
Snippet Manager
manage your snippets
Intercity
web-based Dokku deployment
SmartVPN Billing
billing management for hosting
Brimir
an email helpdesk
Twist
book review application
C2
approval process automation
Xrono
asset and time-tracking
JobsWorth
Project management, time tracking, billing
Trado
simple e-commerce platform for developers
Heaven
github flow orchestrator
adopt-a-hydrant
adopt-a-hydrant software
Case File Editor
editor for digital case files
Lewsnetter
email marketing application
AskThem
monitor and interact with local government
Squash
exception reporting and bug analysis by Square
GitLab CI
continuous integration server
uk-postcodes
postcodes application
Helpful
simple and elegant support system
Do Continuous Integration Yourself
open-source CI server
Teambox
the original teambox.com
RailsCasts
RailsCasts.com source code (thanks Ryan)