| Abel-Technik e.K. | Lower Saxony |
| Abelnet | Hesse |
| Abelssoft Ascora GmbH | Lower Saxony |
| Abenaa Design 2.18 | Bavaria |
| Aberle GmbH | Baden-Württemberg |
| ABF Software-Systeme GmbH | Hesse |
| Abidat GmbH | Bavaria |
| Abilis GmbH IT-Services & Consulting | Baden-Württemberg |
| ABIS GmbH | Hesse |
| Abisys GmbH | |
| abk-technology GmbH | Hesse |
| Ableton | |
| Abnoba GmbH | |
| ABO Wind | |
| ABOnetX | North Rhine-Westphalia |
| Aborange.de | Hesse |
| abp Automationssysteme GmbH | Hesse |
| ABP Induction Systems GmbH | |
| Abraxas Medien Hamm & Wächter GbR | Bremen |
| ABS Systemberatung Verwaltungs GmbH | Baden-Württemberg |
| Absend.net | |
| ABSICHT GmbH | |
| AbsInt | Saarland |
| Absolut Digital 2.0 GmbH | |
| Absolut Research GmbH | |
| Absolute Media GmbH | North Rhine-Westphalia |
| Absolute Software GmbH | Hamburg |
| Absoluto GmbH | Hesse |
| abspace | Baden-Württemberg |
| Abstract-Technology GmbH | |
| Abstracto Medienstudio | North Rhine-Westphalia |
| ABSTRAKT design | North Rhine-Westphalia |
| Abteilung Künstliche Intelligenz der Universität Ulm | Baden-Württemberg |
| Abtinet e.K. | |
| Abtis GmbH | Baden-Württemberg |
| Abtwittern | Saxony |
| ABX-CRO | Saxony |
| Abylonsoft | Rhineland-Palatinate |
| AB_DATE Engineering Software | North Rhine-Westphalia |
| AC Süppmayer GmbH | Saarland |
| AC-Systems GmbH | |
| ACA GmbH | Baden-Württemberg |
| Academa GmbH | |
| Academy Design | Bavaria |
| Acadon AG | North Rhine-Westphalia |
| Acandis GmbH | |
| Acantara | North Rhine-Westphalia |
| Acardo Group AG | |
| ACC electronic HUTH | Bavaria |
| accadis Bildung GmbH | |