x10mp3 is a plugin for XMMS to control it using X10's Mp3Remote, which comes with Mp3Anywhere, Mp3Anywhere 2000, or DVDAnywhere. It has all the functionality of X10's BOOM2000 software for Windows, plus other handy features like muting, skipping around inside tracks, and balance control.
x11vnc allows one to remotely view and interact with real X displays (i.e. a display corresponding to a physical monitor, keyboard, and mouse) with any VNC viewer. It is designed to be compatible with all Unix variants and Mac OS X, and depends on a small set of standard libraries. It supports SSL/TLS and VeNCrypt encryption, Unix password logins, single port access, Zeroconf, file transfer, and UltraVNC extensions. It is part of the LibVNCServer project.
x2search is a crawler based on machine learning algorithms that finds pages and documents that are similar to given positive and different to given negative examples. The learned classifiers can be exported and saved for later reuse. It features multiple settings for searching by domain/server, etc. and has a plug-in mechanism for adding document types to be searched.
x2vnc is an implementation of the VNC RFB protocol designed to control a machine running a VNC server in a dual-monitor situation. Its effect is to make the controlled machine's display function as if attached to the controlling machine, allowing the use of just one set of input devices on two or more machines.
xAutoClick is an autoclicker application that enables you to automatically click the left mouse button. It is designed to reduce strain on the wrist muscles caused by repetitive mouse clicking, which can lead to serious injury or impairment (RSI, Carpal Tunnel Syndrome, et cetera). By specifying the interval, a random factor and the number of times to click, the program simulates natural clicking.