xlayout is a terminal-based utility to get and set information about X11 windows and the pointer. It's designed to be easily integrated into bash shell scripts and takes advantage of the X11 protocol to allow it to access remote X11 desktops. With the aid of the libease library, xlayout provides the ability to smoothly ease the windows and pointer into position.
xlife is a laboratory for experimenting with cellular automata. It supports loadable rulesets and palettes, different topologies, and up to 256-state cellular automata. It has rules and patterns for Life, Brian's Brain, Perrier's Loops, Langton's Ants and Loops, Wireworld, E.F. Codd's 1975 UCC automaton, some Prisoner's Dilemma games, and many others. It is very fast for step-by-step mode, bounded grid, and chaotic patterns. It has several unique features: a historical mode, a pseudocolor mode, and n-state statistics. It has been developed since 1989. The modern version of Xlife began its history in 2011.
xlike is a patch collection for the Linux vanilla kernel. It includes as many stable enhancements for the Linux kernel as possible. These include code from Xen, Kernel Mode Linux, Rule Set Based Access Control, Novell AppArmor, Openswan, grsecurity, Linux VServer, Linux-PHC, web100, Nefilters, Suspend2, Speakup, SquashFS, UnionFS, Bootsplash, BadRAM, and more. It also contains many drivers and fixes.
XLocate greatly extends the usability of standard Linux slocate or GNU locate utilities. It allows for instant search of fixed strings or regexps in file names from local and remote, mounted or unmounted filesystems, as well as any number of memory sticks, removable drives, CD-ROMs, and data DVDs. It compiles natively on Qt4 and Qt3, without Qt3 compatibility required for the former.
xmailheaders is a mail notification utility that is based on the "mailbox" utility that's avilable on Solaris workstations. The idea is that it sits on your desktop somewhere, periodically polling the mail server/spool for new messages. New message headers are displayed as they come in. Supported mailbox formats are POP3, IMAPv4, and Unix mbox. SSL-based password authentication is also supported for POP and IMAP.