Information Security - Applications

Ad-Aware Free Antivirus+
BlackArch Linux
Comodo (tons of stuff, much of it free)
DigiNinja
Kahu Security
Kali Linux
Kippo
Let's Encrypt
Lightweight Portable Security (LPS) Linux
Malwarebytes
Microsoft Safety and Security Center
ModSecurity
Network Security Toolkit (NST)
NSA Playset
Off-the-Record Messaging (OTR)
OpenSSH
OpenSSL
PeaZip
Qubes OS
Samhain Labs
Security Onion
Shmoo Group
Subgraph OS
Sysinternals
Tails OS
ZMap