- X-1R Corporation (Daytona Beach, FL)
- X-Act Technology, Inc. (Erie, PA)
- X-COM Systems (Reston, VA)
- X-Digital Systems Inc. (San Diego, CA)
- X-energy (Greenbelt, MD)
- X-Es, Inc (Middleton, WI)
- X-Fab (Lubbock, TX)
- X-Microwave, LLC (Austin, TX)
- X-Nav Technologies, LLC (Lansdale, PA)
- X-REL Semiconductor (Grenoble, FRA)
- X-Rite, Inc. (Grand Rapids, MI)
- X-Tek Group, Inc. (Tyngsboro, MA)
- X-Tel Communications, Inc (Lombard, IL)
- X.Labs (West Hollywood, CA)
- X1 Enterprise Search (Pasadena, CA)
- X2 Biosystems, Inc. (Redwood City, CA)
- X2 Enterprises (Los Angeles, CA)
- X360 Software (hong kong, HKG)
- Xact Wire EDM Corp. (Waukesha, WI)
- Xactly Corporation (San Jose, CA)
- Xait (Austin, TX)
- Xaloy, Inc. (Pulaski, VA)
- XALT Energy (Midland, MI)
- XALT Energy (Midland, MI)
- Xalyo Systems (Gland, CHE)
- Xandex (Petaluma, CA)
- Xantrex Technology, Inc. (Arlington, WA)
- Xata Corp. (Eden Prairie, MN)
- Xaware Inc. (Colorado Springs, CO)
- xBML Innovations, Inc. (Englewood, CO)
- XCBA Maritime Software Inc. (Cheltenham, AL)
- Xccent (Wyoming, MN)
- Xceedid Corp (Golden, CO)
- Xceedium (Jersey City, NJ)
- Xcellerex, Inc (Marlborough, MA)
- XCEND Group (Brighton, MI)
- Xcentric Mold & Engineering, Inc. (Clinton Twp, MI)
- Xcerra Corp. (Norwood, MA)
- XCMG (Nanjing, CHN)
- XCMG (Las Vegas, NV)
- XConnect (London, GBR)
- Xcor Aerospace, Inc. (Mojave, CA)
- XCPT, LLC (Venice, FL)
- Xecom Inc. (Milpitas, CA)
- Xeeva (Madison Heights, MI)
- XEI Scientific, Inc. (Redwood City, CA)
- Xelltec Inc. (Wilmington, DE)
- Xemplar Insights (Wayne, PA)
- XENA Networks (Framingham, MA)
- Xencor, Inc. (Monrovia, CA)
- Xenetech USA, Inc. (Baton Rouge, LA)
- Xenith Solutions (Reston, VA)
- Xeno (Berkshire, GBR)
- Xenon Corp. (Wilmington, MA)
- Xenon Inc. (Irvine, CA)
- Xenos Group (Richmond Hill, ON, CAN)
- Xenos Software (Murfreesboro, TN)
- Xenosep Technologies, LLC (Boonton, NJ)
- Xentris Wireless, LLC. (Addison, IL)
- Xequte Software (Wellington, NZL)
- Xero (Wellington, NZL)
- Xeround Systems (Yehud, ISR)
- Xerowaste Solutions, Inc. (Vancouver, BC, CAN)
- Xerox Corp. (Palo Alto, CA)
- Xerox Corporation (Fairport, NY)
- Xerox Imaging Standards (Norwalk, NY)
- XetaWave, LLC (Louisville, CO)
- Xeye (New York, NY)
- XFX (Ontario, CA)
- XG Sciences, Inc. (Lansing, MI)
- xG Technology, Inc (Hackettstown, NJ)
- Xi Graphics, Inc. (Denver, CO)
- Xiamen Set Electronics (Xiamen, CHN)
- Xiameter (Midland, MI)
- Xicato (Los Gatos, CA)
- XID Technologies Pte Ltd (Tan Chong Tower, SGP)
- Xign (Pleasanton, CA)
- Xilinx, Inc. (San Jose, CA)
- Xilinx, Inc. (Sunnyvale, CA)
- XiloCore (Las Vegas, NV)
- XIMEA Corp. (Golden, CO)
- XiMeta Technology, Inc. (Fremont, CA)
- Xinde Technology Company (Weifang City, CHN)
- Xinet, Inc. (Berkeley, CA)
- Xing Tone (Los Angeles, CA)
- Xinuos (St Croix, VI)
- Xiom Corp. (Babylon, NY)
- Xiotech Corp. (Colorado Springs, CO)
- XIRING (Suresnes Cedex, FRA)
- Xiris Automation Inc. (Burlington, ON, CAN)
- Xirrus Inc. (Thousand Oaks, CA)
- Xitron Technologies, Inc (San Diego, CA)
- XIUS (Woburn, MA)
- XJTAG Inc (Waltham, MA)
- XKL, LLC (Kirkland, WA)
- XL Group (Stamford, CT)
- XLAB d.o.o. (Ljubljana, SVN)
- Xlink Technology, Inc. (Milpitas, CA)
- XLR8 Mobile, Inc., (San Francisco, CA)
- XM Satellite Radio (Washington, DC)
- XML Technology Certification Committee (Tokyo, JPN)
- XMLAuthor, Inc. (Draper, UT)
- Xmod Technologies (Talence, FRA)
- XMPie, Inc. (New York, NY)
- Xmultiple (Simi Valley, CA)
- XO Communications (Herndon, VA)
- Xodtec LED, Inc (Taipei, TWN)
- Xoft, Inc. (Sunnyvale, CA)
- XOi Technologies (Nashville, TN)
- Xojo, Inc. (Austin, TX)
- XOLUTION GmbH (Munich, DEU)
- Xometry, Inc. (Rockville, MD)
- XOP Networks, Inc. (Dallas, TX)
- Xoptix Limited (Malvern, GBR)
- Xorcom Ltd. (Phoenix, AZ)
- XOS (East Greenbush, NY)
- Xosoft, Inc (Waltham, MA)
- XoYo Software (Tianjin, CHN)
- XP Power (Sunnyvale, CA)
- XP Smoker (Annville, PA)
- Xpedion (Milpitas, CA)
- xpedx (Loveland, OH)
- XPerience Technologies (Krasnodar, RUS)
- XPiQ (Holliston, MA)
- xPLM Solution, Inc. (Three Rivers, MA)
- Xplore Technologies (Austin, TX)
- Xpndbls (Lake Forest, CA)
- XpoLog (Kfar Truman, ISR)
- Xpress Software, Inc. (Vaughan, CAN)
- Xramp (San Antonio, TX)
- XrayCurtains.com (The Woodlands, TX)
- XRI (Houston, TX)
- XRoads Networks (Irvine, CA)
- XRT (Wayne, PA)
- Xsens Sports Technologies B.V. (NLD)
- XSENSOR Technology Corp. (Calgary, AB, CAN)
- Xsight Systems Ltd. (Rosh Haayin, ISR)
- XSP (London, GBR)
- Xspect Solutions, Inc (Wixom, MI)
- XSPlatforms (Gorinchem, NLD)
- Xstatic, LLC (Newton, AL)
- Xtalic Corporation (Marlborough, MA)
- XTec, Inc. (Miami, FL)
- Xten Industries (Kenosha, WI)
- Xtend (Vienna, VA)
- Xtenit (New York, NY)
- XTM International (London, GBR)
- Xto Energy Inc. (Fort Worth, TX)
- Xtra Lease (Saint Louis, MO)
- Xtract Corporation Ltd (Bracknell, GBR)
- Xtralis (Norwell, MA)
- Xtreeme GmbH (CH-2800 Delémont, CHE)
- Xtreme Graphics (Inver Grove Heights, MN)
- Xtreme Power (Austin, TX)
- XTS Inc (Ellicott City, MD)
- xTuple (Norfolk, VA)
- Xuron Corp. (Saco, ME)
- Xuyi Botu Attapulgite Clay High-Tech Development Co.,Ltd (Nanjing, CHN)
- XVEL Software (Kiev,, UKR)
- XxPansion Networks, Inc. (Knoxville, TN)
- Xycom Automation Inc. (Saline, MI)
- XyEnterprise, Inc. (Reading, MA)
- Xylem Flow Control (Irvine, CA)
- Xylem, Inc. (Rye Brook, NY)
- Xylem, Inc. (Rye Brook, NY)
- Xyleme, Inc. (Denver, CO)
- Xymox Technologies Inc. (Milwaukee, WI)
- Xyntek Inc. (Yardley, PA)
- Xyratex International, Ltd. (Brentwood, NH)
- Xyratex Ltd. (San Jose, CA)
- Xythos Software (San Francisco, CA)
- XYZprinting (San Diego, CA)
- XYZprinting, Inc. (San Diego, CA)
- XZERES Corp. (Wilsonville, OR)