Pfsense is a free, open-source customized distribution of FreeBSD specifically tailored for use as a firewall and router that is entirely managed via a web interface.
Cryptomator.
Cryptomator is an open-source encryption tool for secure cloud storage. Protect your privacy for free on Dropbox, Google Drive, OneDrive, and more.
Ente.
Ente is a service that provides a fully open source, end-to-end encrypted platform for you to store your data in the cloud without needing to trust the service provider.
Signal is a simple, powerful, and secure messenger.
State-of-the-art end-to-end encryption (powered by the open-source Signal Protocol) keeps your conversations secure
Continuous file synchronization
Syncthing is an open-source continuous file synchronization program. It synchronizes files between two or more computers in real time and is encrypted.
Open source diagram tool
A free, open-source diagramming software used for creating a wide variety of diagrams such as flowcharts, process diagrams, network diagrams, and more.
Open Source Real-Time Monitoring Dashboard
Troubleshoot slowdowns and anomalies in your infrastructure with thousands of per-second metrics, meaningful visualizations, and insightful health alarms with zero configuration.