The MD5 message digest library implements the MD5 message digest algorithm specified in RFC 1321 directly from the specification, without copying from the reference implementation and therefore without requiring mention of RSA when used. It uses the same unrestricted-distribution license as zlib.
Xtradius is a radius server that permits you to handle user authentication and accounting request via external scripts. You can handle script requests for user accounting, user authentication, NAS start and NAS stop packets. You can also write additional information into the NAS detail logfile. Parameters to scripts are passed via command line options or environment variables, making it very simple to implement SQL-based user accounting, authentication and account expiration. It is also compatible with "standard" cistron radius server.
Mason is a tool that interactively builds a firewall using Linux' ipfwadm or ipchains firewalling. You leave mason running on the firewall machine while you are making all the kinds of connections that you want the firewall to support (and want it to block). Mason gives you a list of firewall rules that exactly allow and block those connections. It can either build a firewall from scratch for you or supplement an existing firewall.
vpnd is a daemon which connects two networks on network level either via TCP/IP or a (virtual) leased line attached to a serial interface. All data transfered between the two networks are encrypted using the unpatented free Blowfish encryption algorithm with a key length of up to 576 bits (may be downgraded to a minimum of 0 bits to suit any legal restrictions).