Great Open Source Server Software

Advanced self-hosted tool for tracking uptime across multiple services with reactive UX, interval checks, various notifications, and multi-language support.

OpenSSH is a free version of the SSH connectivity tools that technical users rely on. OpenSSH encrypts all traffic (including passwords) to effectively eliminate eavesdropping, connection hijacking, and other attacks.

Open-source HTTP server offering cross-platform support, modular architecture, secure configuration, robust content delivery, and extensive authentication features.

nginx ("engine x") is an HTTP web server, reverse proxy, content cache, load balancer, TCP/UDP proxy server, and mail proxy server.

PostgreSQL is a powerful, open source object-relational database system with over 35 years of active development that has earned it a strong reputation for reliability, feature robustness, and performance.

MariaDB is a backward compatible, drop-in replacement of the MySQL® Database Server. It includes all major open source storage engines.

Matrix defines a set of open APIs for decentralised communication, suitable for securely publishing, persisting and subscribing to data over a global open federation of servers with no single point of control.

Healthchecks.io is a service for monitoring cron jobs and similar periodic processes:

Cachet is a simple to use and easy to manage status page system and can be easily installed and used to track third party service letting your users know what's going on.