Mailtrain : Mailtrain is a self hosted newsletter application built on Node.js (v5+) and MySQL (v5.5+ or MariaDB). Mailtrain supports subscriber list management, ...
Gerrit : Web based code review and project management for Git based projects.
Cachet : Beautiful & simple service statuses. The open source status page system, for everyone.
Mattermost : Mattermost is a self-hosted solution for bringing all your team communication to one place, and making it searchable and accessible anywhere
Documize : Documize is an open source modern, lightweight and comprehensive alternative to Confluence.
It's built with Golang + EmberJS and compiled down to a si...
GitLab is a web-based Git repository manager with wiki and issue tracking features. GitLab offers hosted accounts similar to GitHub, but also allows its software to be used on third party servers.