Best Linux Free Open-Source Security Software

Private, end-to-end encrypted messaging.

A note-taking app with a focus on security and simplicity

Simple vaultless password manager in Go

Free backup software to store encrypted backups online

A simple, fast, and secure note-taking app

Cross-platform password manager compatible with Keepass 2.x

A secure password manager for teams

Deduplicating backup solution

Fast, secure, efficient backup program

Network-wide ad blocking DNS server for homes and small businesses

Fast and secure backup and versioning for files and directories

Network-wide ads & trackers blocking DNS server

Secure, fast file transfers from the command line

Lightweight Intranet Penetration Proxy Server

Interactive, scriptable man‑in‑the‑middle proxy for HTTP, HTTPS and WebSocket traffic

General purpose TLS and crypto library

Open-source antivirus engine for detecting malware across platforms

High-performance reverse proxy for NAT traversal

Secure and fast microVMs for serverless computing

An open platform for various uses

Secure dotenv for developers

Interactive application firewall for GNU/Linux

A modern, secure password manager

A fast, secure, minimalist note‑taking app for students and freelancers