| Prefix | Organization | Purpose | Web Site | Contact | Registered |
|---|---|---|---|---|---|
| X | Informatica Consultancy and Development | CodeX; X | www.informatica.uk.com | Dave Collie | 10-Jul-1998 |
| X | Krzysztof Szyszka | X-Files Components | kszyszka.republika.pl | Krzysztof Szyszka | 07-Feb-2002 |
| X2 | (misc) | Melle Slotema | 22-Jul-2000 | ||
| xa | Delphi Shop Seven Pte Ltd | VizAcc Accounting System | cc.embarcadero.com/Item/20601 | Peck Kim Han | 19-Sep-2001 |
| xcl | aiXtrusion | TxclNumInput | www.aixtrusion.de | Marcus Schlueter | 20-Feb-2004 |
| XDK | Borland Russia | XDK Experts; Wizards | www.linkedin.com/in/sorlik | Sergey Orlik | 30-Dec-1899 |
| XL | Gavina International Inc. | TXLGrid | www.gavina-software.com | Alexey Lavnikov | 29-Oct-1999 |
| XLS | Axolot Data | XLSReadWrite | www.axolot.com | Lars Arvidsson | 31-Jul-1999 |
| XM | Various visual and non visual components | mh-nexus.de | Maël Hörz | 11-May-2003 | |
| XML | XMLWorks | www.pbe.com/SourceWorks/XMLWorks | Marc Bir | 23-Jul-1999 | |
| xp | rhoStyle | xpStyle | www.rhostyle.com | Roman Lysov | 20-May-2004 |
| XR | Mensand | XML R | http://www.rapware.nl/ | Andre Mens | 17-Aug-2000 |
| XW | Xapware Technologies Inc. | xwComps | www.xapware.com | Xavier Pacheco | 06-May-1999 |
| XY | Kestral Computing Pty Ltd | TxyGraph; Graphics | www.kestral.com.au/delphi/ | Grahame Grieve | 30-Dec-1899 |
| XYZ | Klankschap | reserved | Floris van Manen | 01-Mar-2002 |