- A-DATA
- A-Solar
- A4Tech
- Aavara
- Acco
- Acomdata
- Acoustic Energy Ltd
- Acronis
- ACT
- Activision
- Adata
- Adder
- Addison
- Adesso
- ADS Tech
- Aesp
- AGFEO
- Agipa
- AGM
- Agrodolce
- Ahead
- Aladdin
- Alanbridge
- Albatron
- Albumteam
- Alcatel
- Alk
- Allied Data
- ALPS
- Alta4
- Altusen
- Amacom
- AMCC
- American Tourister
- AMW
- Anders+kern (a+k)
- Anir
- Ansmann
- Antazone
- Anysee
- AOC
- APlus
- AplusCase
- Apm
- Apo
- Appsense
- Aqua computer
- Areca
- Argosy
- ArkticFreeze
- Armor
- Asi
- Ask Proxima
- ASSMANN Electronic
- Astaro
- At Mobile
- Atari
- Atec
- Aten
- Atto
- Auerswald
- Auras
- Autodesk
- Avaya
- Avery Laser Labels
- Avira
- Avision
- Axis Communication
- AXP
- Axper
