| Xeko GmbH | Schleswig-Holstein |
| Xelera Technologies GmbH | |
| Xell AG | |
| Xellsoft.com | Bavaria |
| Xempus AG | |
| Xenios AG | |
| Xenium AG | Bavaria |
| Xeno-Data GmbH | |
| Xenoage Software | Bavaria |
| XENON Automatisierungstechnik GmbH | |
| Xentasystems GmbH | |
| xentral ERP Software GmbH | Bavaria |
| xeotek GmbH | |
| Xeovision | Hesse |
| Xeror | Schleswig-Holstein |
| Xerox GmbH | North Rhine-Westphalia |
| Xertecs GmbH | |
| XFT GmbH | Baden-Württemberg |
| Xi-Machines GmbH | |
| XignSys GmbH | |
| XimantiX Software GmbH | Bavaria |
| XIMEA GmbH | North Rhine-Westphalia |
| Xindy | Hesse |
| XING | Hamburg |
| Xinux Networks | Rhineland-Palatinate |
| Xion Webdesign | Bavaria |
| XiSys Software GmbH | Bavaria |
| XITASO Holding GmbH | Bavaria |
| XL-protein GmbH | |
| XLETIX GmbH | |
| XLM Software & Webdesign | Bavaria |
| Xmental | Berlin |
| XML Validation | Lower Saxony |
| Xnet Systems | |
| Xodox GmbH | Bavaria |
| XONIC Solutions GmbH | Saxony |
| Xoron GmbH | North Rhine-Westphalia |
| Xortec GmbH | |
| XOVI GmbH | North Rhine-Westphalia |
| xp-AntiSpy | Berlin |
| xpecto Talonec GmbH | Bavaria |
| Xpedite Diagnostics GmbH | |
| XPERIENTS UG (haftungsbeschränkt) & Co. KG | Hamburg |
| Xpert-Design Software | Bavaria |
| Xpert-Soft | North Rhine-Westphalia |
| XPLM Solution GmbH | Saxony |
| XPLN | |
| xplus-media | Lower Saxony |
| XPoint Computerservice GmbH | Berlin |
| Xpoint Software GmbH | Bavaria |