Best Free Open-Source Security Software

Fast, secure, efficient backup program

Fast and secure backup and versioning for files and directories

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

Secure, private budgeting for individuals and households

Comprehensive authentication framework

Secure dotenv for developers

Cross-platform password manager compatible with Keepass 2.x

Lightweight Intranet Penetration Proxy Server

General purpose TLS and crypto library

High-performance reverse proxy for NAT traversal

Safe home for all your data

Privacy-focused Segment alternative

Generate Software Bill of Materials from container images and filesystems

Real‑time spatial intelligence from ordinary WiFi signals

Distributed operating system for blockchain app builders

Bitwarden‑compatible vault hosted on Cloudflare Workers for free

Free backup software to store encrypted backups online

Free open-source Android app for secure 2-step verification tokens.

Secure authentication for Next.js apps

Advanced offline password cracker supporting hundreds of hash types

A secure password manager for teams

A modern, secure password manager

Interactive application firewall for GNU/Linux

Patch-level verification for Bundler