Awesome Privacy

Network-level advertisement and Internet tracker blocking application which acts as a DNS sinkhole. Pi-Hole can significantly speed up your internet, remove ads and block malware. It comes with a nice web interface and a mobile app with monitoring features, it's open source, easy to install and very widely used.

Another DNS server for blocking privacy-invasive content at its source. Technitium doesn't require much of a setup, and basically works straight out of the box, it supports a wide range of systems (and can even run as a portable app on Windows). It allows you to do some additional tasks, such as add local DNS addresses and zones with specific DNS records. Compared to Pi-Hole, Technitium is very lightweight, but lacks the deep insights that Pi-Hole provides, and has a significantly smaller community behind it.

A hardened, versatile, state-of-the-art open source firewall based on Linux. Its ease of use, high performance and extensibility make it usable for everyone.

A simple way to set up a home VPN on any Debian server. Supports OpenVPN and WireGuard with elliptic curve encryption keys up to 512 bit. Supports multiple DNS providers and custom DNS providers - works nicely along-side PiHole.

Powerful open source web content filter.

Widely used, open source firewall/router.

Detect if you have a malware-infected computer on your network, and powerful network analysis framework and monitor.