• Oakridge National Laboratory
• Object Automation
• Object Automation
• Objective Management Group, Inc.
• ObjectSwitch Inc.
• Ocentrix, Inc.
• OCS IntelliTrak
• Octagon Research Solutions, Inc.
• Odotech
• OEA International, Inc.
• OEM America
• Oil Trap Inc.
• Omega II Fence Systems
• Omnilink Systems
• Omnova Solutions, Inc.
• OnCourse Systems for Education, LLC
• O'Neil & Associates
• online-registries, Inc.
• Online Insight
• OPD Solutions
• Onsite Companies
• OPTATE, Inc.
• Open Disc Systems
• Open Engineering
• Open Online
• Open Text Corporation
• OpenVision
• Opsis Techologies
• Optel Vision
• Optex Communications
• Optimal Blue
• OptiMark Technologies, Inc.
• Optimer, Inc.
• Optum
• Opus360 Corporation
• Opus360 Corporation
• Oracle Corporation
• Oracle Corporation
• Oracle
• Orbis Financial
• ORCHESTRATE
• Orchestream
• ORENCO
• Organetix
• Orica Watercare
• Origen Financial LLC
• The Original SWAT
• Original S.W.A.T. Footwear
• Orthosonix, Inc.
• oto Global Solutions Inc.
• The Outernet
• OutlookSoft Corporation
• Owens Corning Automotive