Cachet : Beautiful & simple service statuses. The open source status page system, for everyone.
sovereign : A set of Ansible playbooks to build and maintain your own private cloud: email, calendar, contacts, file sync, IRC bouncer, VPN, and more.
SimpleLogin : With email aliases , you can be anonymous online and protect your inbox against spams and phishing. Open-source.
ProjectPier.org : ProjectPier is a Free, Open-Source, PHP application for managing tasks, projects and teams through an intuitive web interface. It must be downloaded a...
Commento : A lightweight, open source, tracking-free comment engine alternative to Disqus.
Open source meeting scheduling tool. Send a link, let others book a slot. Calendly alternative.