| 9elements GmbH | North Rhine-Westphalia |
| 9x | |
| :em engineering methods AG | Hesse |
| @-web | Brandenburg |
| @TOLL GmbH | Baden-Württemberg |
| A & G Automation and Gears GmbH | Schleswig-Holstein |
| A Color Bright GmbH | |
| a tempo Satz & Verlag GmbH | North Rhine-Westphalia |
| A&B One Digital GmbH | Berlin |
| A&S Kopiersysteme GmbH | North Rhine-Westphalia |
| A+B Solutions GmbH | Baden-Württemberg |
| A-MEC | North Rhine-Westphalia |
| A-Solution Gesellschaft für Mess- und Automatisierungslösungen mbH | Bavaria |
| a-tune Software AG | Hesse |
| A. ARNOLD ELECTRONIC Vertretungs- + Vertriebs GmbH | North Rhine-Westphalia |
| A. Klünder e.K. | |
| A. M. Ramp & Co GmbH | Hesse |
| a.b.media GmbH | Lower Saxony |
| a.b.s. Rechenzentrum GmbH | Bavaria |
| A.C.T. Computer TEAM | Berlin |
| A.K.E Software GmbH | North Rhine-Westphalia |
| A.M.D. Telekommunikations GmbH | |
| A.M.E.C.C. GmbH | |
| A.P. Computerdienst | North Rhine-Westphalia |
| a.p.medien GmbH | Baden-Württemberg |
| A.R. BAYER DSP Systeme GmbH | North Rhine-Westphalia |
| A.T.i. Software GmbH | Bavaria |
| A/C/T Beratungs & System GmbH | Bavaria |
| A1 Professional Software GmbH | Bremen |
| A2C Software AG | North Rhine-Westphalia |
| A2D3 | Bavaria |
| a4 - Computer und Informationssysteme | Saxony-Anhalt |
| a4kom e.K. | Hesse |
| A4VR GmbH | |
| A7soft | Bavaria |
| AAA Computer + Electronic GmbH | Baden-Württemberg |
| AAAHosting GmbH | Baden-Württemberg |
| AAB Management GmbH | |
| AABBOO GmbH | Hesse |
| AAC Kabelbearbeitungssysteme GmbH | North Rhine-Westphalia |
| Aachener Linux User Group | North Rhine-Westphalia |
| Aagon Consulting GmbH | North Rhine-Westphalia |
| aam it GmbH | |
| Aampere GmbH | |
| Aana | |
| aap Implantate AG | |
| Aareal First Financial Solutions AG | |
| Aareon AG | Rhineland-Palatinate |
| aaris c² | |
| Aaron GmbH | |