Linux
THIS IS THE MEAT AND POTATOES OF THE POST, THE REST IS JUST DESERT!!
secureblue - Currently The Best Security Focused Desktop And Server Linux Operating System, it's based on Fedora (You still need to follow their guides to harden it further) Use Trivalent browser (currently only supports secureblue) to fully harden your OS.
Lynis - Linux/ MacOS hardening Auditing tool
Linux Hardening - Hardening Linux
ansible-collection-hardening - Linux Hardening guides and tools
Privacy.sexy - Name might look sus, but it has lists of objectives to look for
How to Secure a Linux Server - Documentation on securing a server
Guides
WhoAmI Project - Privacy / Anonymity Tool
ArchWiki - Linux Guide Manuals TUI
Gentoo Wiki - Gentoo Wikis
Debian Wiki - Debian Wiki
LinuxJourney - Interactive Linux Guides
HowToLinux - Linux Desktop Guides
Boot-Repair - Grub Repair Guide for Linux Systems
Linux Command Library - Showcases and explains some terminal commands (Useful for starting out)
Password Privacy / 2FA (2 Factor Authentication)
Ente Auth - 2FA
Aegis - 2FA
Stratum - 2FA
Bitwarden - Password Managers
Proton Pass - Password Managers
DNS Adblocking
Mullvad DNS - DNS Adblocking
NextDNS - Customizable DNS Adblocking Service
AdGuard DNS - Customizable DNS Adblocking Service
DNSWarden - DNS Adblocking
VPN
Mullvad VPN - Paid
IVPN - Paid
NYM - Paid
Firewall
OpenSnitch - Linux Firewalls (IDK why but Linux usually doesn't have a working firewall out of the box, always look if the firewall is up!)
Tracee - Runtime Security and Forensics
vnStat - Network Monitors
USBGuard - Implement USB Device Authorization Policies (IDK where to place this)
GoogleTeller - Google Tracking Notifications
Sandboxing
Firejail - Sandboxing Tools
Bubblewrap - Sandboxing Tools
Triage - Online Sandboxes
Cuckoo - Online Sandboxes
SquareX - Online Sandboxes
Clients
mx moment - Encrypted Chat Client
gurk-rs - Signal Client
ZapZap - WhatsApp Client
YouTube-Viewer, Pipe Viewer, Pipeline - YouTube Clients
GrayJay - Combines YouTube, Twitch, Rumble etc
BetterDiscordctl - Modded Discord Client
Discover - Discord Overlay
File Tools
syncthing - continuous file synchronization program between two or more computers in real time
Warpinator - Share files across the LAN
rQuickshare - NearbyShare/QuickShare from Android for Linux and macOS.
Dolphin, SpaceFM - File Managers
Collector - File Drag \& Drop
p7zip, GNU Gzip, pigz - File Archivers / Unzippers
Pika Backup, RecoverPy - File Backup / Reocovery Tools
FSLint, kdiff3, fclones - Duplicate File Finder
xdg-ninja - Unwanted File Finder
gscan2pdf - Turn Documents into PDFs
Window Managers
Hyprland - Wayland Compositor Resources Arch Wiki Simple Config (Alternate Link)
i3wm, BSPWM, herbstluftwm - Tiling Window Managers
awesomewm, xmonad, Qtile, dwm - Dynamic Window Managers
File Scanners
VirusTotal - Online File Scanner
Hybrid Analysis - Online File Scanner