AppPerf
application and performance monitoring tool
Bike Index
the internet's bike registry
Catarse
open-source crowdfunding platform
Central
Fulcrum project planning tool fork
Chatwoot
customer engagement platform
Discourse
next-generation discussion platform
Ekylibre
farm management information system
exercism.io
code practice and mentorship
forem
the platform that powers dev.to
HyperCable
analytics
MarkUs
submission and grading for student assignments
nindika.com
nintendo switch e-shop
Open Source Billing
Beautifully Simple Billing Software
Open Split Time
endurance event data management
Pig CI
Rails performance monitoring, plus CI
PublicLab.org
collaborative knowledge-exchange platform
Punchclock
simple electronic punch clock
rubytoolbox.com
catalog of all Rubygems that keeps track of popularity and health metrics
TaxonWorks
workbench for biodiversity informatics
Violet
automation, CMS, blog, forum and email thing.
WikiEduDashboard
course dashboard system