| Name | Country | Market Cap (US$) |
|---|
| Nuesoft Technologies, Inc. | United States | Private |
| NuGenesis Technologies Corporation | United States | Private |
| Numerical Technologies, Inc. | United States | Private |
| NuTech Solutions, Inc. | United States | Private |
| NuView Systems, Inc. | United States | Private |
| NuView, Inc. | United States | Private |
| Nuvio Corporation | United States | Private |
| O'Pin Systems Software Products Co. | United States | Private |
| Oak Telecom Limited | United Kingdom | Private |
| Oasis Technology Limited | Canada | Private |
| OATSystems, Inc. | United States | Private |
| Obian, Inc. | United States | Private |
| Object Reservoir, Inc | United States | Private |
| ObjectFX Corporation | United States | Private |
| Objectif Lune Inc. | Canada | Private |
| Objectivity, Inc. | United States | Private |
| ObjectVideo | United States | Private |
| Objecutive, Inc. | United States | Private |
| Oblix, Inc. | United States | Private |
| Obsidian Software, Inc. | United States | Private |
| Occam Direct Marketing Limited | United Kingdom | Private |
| Oce Printing Systems USA, Inc. | United States | Private |
| Ocean Systems Engineering Corporation | United States | Private |
| Oceanwide Inc. | Canada | Private |
| Olive Software, Inc. | United States | Private |
| OmniPod, Inc. | United States | Private |
| On-Site Computer Solutions, Inc. | United States | Private |
| ONCE Corporation | Canada | Private |
| Oncontact Software Corporation | United States | Private |
| OnDemand Software, Inc. | United States | Private |
| OnDisplay, Inc. | United States | Private |
| OneMind Connect, Inc. | United States | Private |
| OneTouch Systems, Inc. | United States | Private |
| OnRamp Access, Inc. | United States | Private |
| OnRelay Limited | United Kingdom | Private |
| Onset Technology, Inc. | United States | Private |
| ONStor, Inc. | United States | Private |
| Ontrack Systems Limited | India | Private |
| Onyx Software Corporation | United States | Private |
| Open Channel Solutions | United States | Private |
| Open Country Inc. | United States | Private |
| Open Link Financial, Inc. | United States | Private |
| Open Port Technology, Inc. | United States | Private |
| Open Ratings, Inc. | United States | Private |
| Open Software Solutions, Inc. | United States | Private |
| OpenAir, Inc. | United States | Private |
| OpenConnect Systems, Inc. | United States | Private |
| Openet Telecom Inc. | Republic of Ireland | Private |
| OpenLink Software, Inc. | United States | Private |
| Openpages, Inc. | United States | Private |
| Optas, Inc. | United States | Private |
| Optiant, Inc. | United States | Private |
| Optical Image Technology, Inc. | United States | Private |
| Optika, Inc. | United States | Private |
| Optima Technology Corporation | United States | Private |
| Optimal Corporation | United States | Private |
| Optimal Networks Corporation | United States | Private |
| Optimal Solutions, Inc. | United States | Private |
| Optimus Corporation | United States | Private |
| Optiwave Corporation | Canada | Private |
| Oracle (UK) Ltd. | United Kingdom | Private |
| Oracle Corporation of Canada Inc. | Canada | Private |
| Oracle E M E A Management | United Kingdom | Private |
| Oracle France S.A. | France | Private |
| Oracle Nederland B.V. | Netherlands | Private |
| Oracle Systems Hong Kong Limited | Hong Kong | Private |
| Orbis Technology Ltd | United Kingdom | Private |
| Orca Interactive Ltd | Israel | Private |
| OrCAD, Inc. | United States | Private |
| Orchard Software Corporation | United States | Private |
| Orchestream Holdings plc | United Kingdom | Private |
| Orion Technologies Inc. | United States | Private |
| Ormed Information Systems Limited | Canada | Private |
| Orsus Solutions, Limited | United States | Private |
| OSA Technologies, Inc. | United States | Private |
| Osaka Gas Info. System Research Ins. | Japan | Private |
| Osellus, Inc. | Canada | Private |
| OSI Software, Inc. | United States | Private |
| Osisoft, Inc. | United States | Private |
| Osmose Holdings, Inc. | United States | Private |
| OTES Consulting | United States | Private |
| OTF Group, Inc. | United States | Private |
| OTG Software, Inc. | United States | Private |
| Ounce Labs, Inc. | United States | Private |
| Outcome Concept Systems, Inc. | United States | Private |
| Outcome Sciences, Inc. | United States | Private |
| OuterBay Technologies, Inc. | United States | Private |
| OutlookSoft Corporation | United States | Private |
| OutStart, Inc. | United States | Private |
| Outtask.com, Inc. | United States | Private |
| Ovid Technologies, Inc. | United States | Private |
| Ox International, Inc. | United States | Private |
| Oxygen Interactive | United Kingdom | Private |
| OZ Communications, Inc. | Canada | Private |
| Pacific Animated Imaging Corporation | United States | Private |
| Pacific Data Designs, Inc. | United States | Private |
| Pacific Edge Software, Inc. | United States | Private |
| Pacific Softworks, Inc. | United States | Private |
| Paciolan Inc | United States | Private |
| PacketHop, Inc. | United States | Private |
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