Zulip : Powerful slack-like open source group chat
Plausible Analytics : Plausible is a lightweight and open-source website analytics tool. It doesn’t use cookies and is fully compliant with GDPR, CCPA and PECR.
Mailtrain : Mailtrain is a self hosted newsletter application built on Node.js (v5+) and MySQL (v5.5+ or MariaDB). Mailtrain supports subscriber list management, ...
Prometheus : Prometheus is an open-source systems monitoring and alerting toolkit originally built at SoundCloud. Prometheus's main features are:
a multi-dimensio...
SimpleLogin : With email aliases , you can be anonymous online and protect your inbox against spams and phishing. Open-source.
Open source meeting scheduling tool. Send a link, let others book a slot. Calendly alternative.