Summary: This article presents a collection of cool but obscure X11 tools for the X Window System, tested on FreeBSD but compatible with other Unix-like operating systems. Some tools include 3D Pong, Angband, AppRes, ASClock, Battalion, Free42, FSV2, GLXGears, GMixer, GVIM, HP-15C, Ico, Mgdiff, MxIco, Micropolis, NEdit, Plan, Sunclock, Ted, TiEmu, WMY2K, WordNet, X026, X48, XAbacus, XAntfarm, XArchiver, XASCII, XBiff, XBill, XBoard, XCalc, XCalendar, XCHM, XChomp, XClipboard, XClock, XClock/Cat Clock, XColorSel, XConsole, XCrySDen, XDiary, XDigger, XEarth, XEdit, Xev, XEyes, XFishtank, XFontSel, XGalaga, Xgc, XInfocom, XInvaders 3D, XKill, XLaby, XLennart, XLess, XLife, XLoad, XLock, XLogo, XMahjongg, XMan, XMascot, XMaxima, XmBibTeX, XMessage, XmGrace, XMH, XMixer, XmMix, XMore, XMosaic, XMOTD, XMountains, XNeko, XOdometer, XOJ, XOSView, Xplore, XPostIt, XRoach, XScreenSaver, XSnow, XSol, XSpread, XStarRoll, Xtacy, XTar, XTerm, XTide, XTrojka, Xv, Xvkbd, XWorld, XWPE, and XZoom.