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).
VTun is the easiest way to create Virtual Tunnels over TCP/IP networks with traffic shaping, compression, and encryption. It is a user space implementation and doesn't need modification of any kernel parts. VTun supports IP, PPP, SLIP, Ethernet, and other tunnel types. VTun is easily and highly configurable; it can be used for various network tasks like VPN, Mobil IP, Shaped Internet access, Ethernet tunnel, IP address saving, etc.
Xclasses is a C layout library for the X Window System. All objects (called gadgets) are font sensitive, i.e. their size changes with the size of the used screen font and the size of the window. All this is done by Xclasses itself. The user may choose any kind of font style and size.
XFMail is an X11 application for receiving electronic mail. It implements most of its email functionality internally so that it does not depend on a lot of extra packages. It supports POP3, MBOX, IMAP4, sendmail, and SMTP. It has built-in support for interfacing with PGP, GPG, ispell/aspell, faces, LDAP, and esound. It runs on most Unix variants.
Xmcd is a full-featured CD player and ripper software suite including xmcd and cda. Both utilities transform your CD drive into a stereo CD player, allowing you to play music CDs on your computer, as well as perform digital audio extraction (DAE) into files or streams of various formats. Multi-disc CD changers are also supported on many platforms. Xmcd features CDDB disc recognition, web browser integration for content related to the playing CD, local discography management, full feature-specific help system, remote control capability, and more.
Xmmix is an audio mixer utility for the X window system using the OSF/Motif interface. It works with the Linux sound driver as well as any UNIX system running the Open Sound System (OSS) driver. Xmmix is user-friendly and has the ability to save/retrieve mixer settings to/from files.
XPilot is a graphical multi-player maneuvering game with less-exciting graphics, but more speed, tactics, and insults. Some people also use it for UDP network analysis. Over the past eight years of playing and development, tons of features have been added to the game, from basic weapons like shotguns and missiles to more recent ones like phasing devices, invisibility, or hyperjump.