Multi-OTP is a PHP class that can be used to authenticate and manage OTP user tokens for strong two-factor authentication. It can create, update, and delete tokens to authenticate users with one time passwords (OTP). The users' data are stored in files. The class can also check the user token using several algorithms: Mobile OTP (MOTP), OATH/HOTP (RFC 4226), and OATH/TOTP HOTP Time Based (RFC 4226 extension). It works with compatible software tokens (iPhone, Android, PalmOS, Nokia, and other Java J2ME capable phones) and hardware tokens (such as Feitian, ZyXEL, Authenex, or Seamoon). The multiotp command line utility is also provided, both in "compiled" form (for Windows) and in source code (for Linux or educational purpose). The multiotp command line can be combined with FreeRADIUS (under Linux) or the free TekRADIUS LT (under Windows) in order to have a powerful radius strong authentication server.
YAMIdentd aims at being a simple, small, and functional ident daemon that can both process local requests and forward requests triggered by masqueraded hosts (when it is running on a Linux gateway). It currently only runs on Linux (2.4 and 2.6, 2.2 untested). The daemon can forward to any ident daemon that accepts forwarded requests. The code aims at being stable, fast, and RFC 1413 compliant. It is meant to be run from inetd. It doesn't use any configuration file. It should do the right thing automagically.
SMRadius is a high performance pre-forked RADIUS AAA server. It features a highly configurable backend engine supporting flexible data specifications. Its primary goal is to provide an extremely flexible authentication platform which may serve a large number of industries, including ISPs and WiSPs.
sec-wall is a feature-packed security proxy that supports SSL/TLS, WS-Security, HTTP Auth Basic/Digest, extensible authentication schemes based on custom HTTP headers and XPath expressions, powerful URL matching/rewriting, and an optional header enrichment. It's a security wall with which you can conveniently fence otherwise defenseless backend servers.