Xoscope (or oscope) is a digital oscilloscope using input from a sound card or EsounD and/or a ProbeScope/osziFOX. Its features include 8 simultaneous signal displays, 1 us/div to 2 s/div time scale, built-in and external math functions including inverse, sum, diff, avg, xy, and FFT, 23 memory buffers, 5 automatic measurements, and file save/load.
xping is a very simple diagnostic tool primarily for system and network administrators. It provides a graphical display of systems and whether or not they are responsive to pings. This information is updated periodically by the tool, and is useful for determining when systems have crashed or there are network faults.
xplain2sql converts files from Xplain to SQL. It supports a very large subset of Xplain, and it can convert from Xplain to Microsoft SQL Server, DB/2, Inprise InterBase, PostgreSQL, Oracle, MySQL 5, SQLite 3 or ANSI-92 SQL. It can also generate an XML description of the generated SQL. This XML description can be used to create low-level middle-tier code. Example stylesheets for Eiffel/ECLI and Delphi/ADO are included. The C source code release should compile on any platform with an ANSI C compiler. There are binary releases for FreeBSD, Linux, Solaris x86, and Windows 2000.
Xplanets is a simulator that shows a spaceship moving through the solar system. The spaceship's movements are influenced by gravity from the sun and the planets according to Newton's laws, and by the acceleration that the engines provide. The planets move around is (simplified) round orbits.
X Persistent Remote Applications (xpra) is "screen for X". It lets you run applications remotely (like ordinary X or VNC), but unlike ordinary X, these applications are "persistent" if you lose your connection, or even if you want to switch to another computer. Also unlike VNC, they are ordinary applications on your desktop managed by your window manager, not trapped in a box.