GnuPG stands for GNU Privacy Guard and is GNU’s tool for secure
communication and data storage.
MaraDNS is a DNS server that strives to be secure and fully
MIMEDefang is a flexible MIME email scanner designed to protect
Windows clients from viruses.
NuFW is an “authenticating gateway”. This means it requires
authentication for any connections to be forwarded through the
Prelude Manager is the main program of the Prelude Hybrid IDS suite.
ProShield is a security program for Debian Linux.
Samhain is an open source file integrity and host-based intrusion
strongSwan is a complete IPsec and IKEv1 implementation for Linux 2.4
and 2.6 kernels
Sussen is a client for the Nessus Security Scanner.
TinyCA is a simple graphical user interface to manage a small CA
yaSSL is an SSL Library for programmers building security
functionality into their applications and devices.