Annict.com
anime website
Autolab
course management and auto-grading of assignments
Bike Index
the internet's bike registry
Chaskiq
full-featured live chat, support, and marketing platform
GitLab
self hosted Git management
Hackathon Manager
hackathon registration and logistics
Helpful
simple and elegant support system
Hitobito
full-scale group hierarchy management
iNaturalist.org
social network for nature stuff
Mastodon
distributed, interconnected microblogging
Notebook Gallery
enterprise Jupyter notebook sharing and collaboration platform
OpenProject
project management system
openstreetmap.org
crowd-sourced map of the world
Outpost
service directories platform
Panoptes
API to support user-defined research projects
samson
Web interface for deployments
Sanataro
household accounting software
Splits.io
speedrunning data and analysis
Upcase.com
learning platform for programming
vglist.co
video game library tracking
visualizer.coffee
visualize hipster coffee machines
World Cube Association
everything for the World Cube Association
zammad
enterprise-ready helpdesk and customer support system