- AAA
- Aberdare Ventures
- ABI Research
- AboutOne
- AboveNet
- ABS Capital Partners
- Acacia Capital Partners
- Accel Partners
- Accel-KKR
- Accenture
- Access (Forms Management)
- Access Industries
- Accion
- Ace Limited
- Acer
- ACI Worldwide
- Activate Networks
- Activision
- Activision Blizzard
- Acxiom
- AdMob
- Adobe
- AdSafe Media
- Advance Publications
- Advantage Capital Partners
- AEC Partners
- Aeria Games
- Agilent
- Aha
- AiHit
- AirStrip Technologies
- Akamai Technologies
- AKimeka
- Alcatel-Lucent
- Alcoa
- Algorithmics
- Alice.com
- Allen & Company
- Allied Minds
- Allos Ventures
- allrecipes
- Alltrails
- ALOK Sanstha
- AlphaNorth Asset Management
- Altair Engineering
- Altera
- Altos Ventures
- Amadeus Capital Partners
- Amazon
- AMC Entertainment
- AMD
- Ameren
- American Civil Liberties Union
- American Express
- Amnesty International
- Amobee
- Analog Devices
- Analysis Group
- Anaren
- Ancestry.com
- Andreessen Horowitz
- AngelList
- AngelPad
- Angry Birds
- Angry Birds Space
- Anobit
- Anthem Ventures
- AOL
- AOL Ventures
- API Technologies
- AppAssure
- AppBridge
- appcelerator
- Appirio
- Apple
- Applied Materials
- Apptio
- Apture
- Archives.com
- Arcsoft
- Arctic Slope Regional Corporation
- ARM Technologies
- Arrowpath Venture Partners
- Ars Technica
- Arsenal Venture Partners
- Arthur Levinson
- Artiman Ventures
- Artisan Creative
- Aruba Networks
- ASIC
- Ask
- Associated Press
- Association of National Advertisers
- Asus
- AT&T
- ATA Ventures
- Atlas Venture
- Atlassian
- atos
- August Capital
- AUO
- Austin Ventures
- Autitude
- Autodesk
- Automated Logic
- Automattic
- Autonomy
- Avago
- Avalon Ventures
- Avaya
- Aviat Networks
- AxialMarket
- Azure Capital Partners