FrazierWall Linux is a single floppy distribution Linux firewall that is based on the Linux Router Project. It is designed for use with ethernet base internet connections (such as cable modems or xDSL lines). It allows you to share such a connection with several other computers on a LAN. It is easy to setup and maintain, and is available in a Linux configurable software version.
KOSd is a modified version of Ascend's RADIUS (derived from Livingston's) daemon that supports GECOS password files in another location than /etc/passwd. The path to the file is configurable in a C file. It's great for segmenting dial-in and email-only users on a dialing pool, supporting both Max units and Xylogics (now Bay) servers from a single password file, and probably others. It will probably work with Cisco or Livingston servers as well by changing the dictionary file and turning off the -DASCEND extensions within the makefile, but you may need to experiment. This product is totally unsupported.
Mod_auth_kerb is an Apache module designed to provide Kerberos user authentication to the Apache web server. Using the Basic Auth mechanism, it retrieves a username/password pair from the browser and checks them against a Kerberos server as set up by your particular organization. It also supports mutual ticket authentication, although most browsers do not support that natively.
Pidentd v3 is a much improved version of the original Ident daemon both in terms of speed, code quality and features. Features include multithreading, a "configure" script, startup autodetection, much clearer/rewritten C code, doesn't run as root after startup, has a configuration file and can be started from /etc/inittab (on systems using a SysV init).