| Open Access to Textbooks for Students | Academic & Science |
| Opportunitites And Tracking System | Business |
| Oil Advisory Technical Services | Business |
| Wild Oats Markets, Inc. | Business |
| Obligations Assimilables du Trésor | Business |
| Options Automated Trading System | Business |
| Order Audit Trail System | Business |
| Olefin Alkylation of Thiophenic Sulfur | Chemistry |
| Outdoor Adventures Through Science | Community |
| Outcomes Assessments And Teaching Strategies | Community |
| Older Adult Transportation Service | Community |
| Over-the-Air Activation TeleService | Computer and Networking |
| Older Adults Technology Services | Computing |
| Oracle Application Testing Suite | Computing |
| Oxford Air Training School | General |
| Organization for App Testing Standards | General |
| Orthogonal Array Testing Strategy | General |
| Open Access Telepresence Systems | General |
| Over Analyzing the Situation | General |
| Official Assassin Travel Sustenance | General |
| Open Area Test Site | Governmental |
| Oral Anecdotes And Testamentary Stories | Governmental |
| O A T S Offering Alternative Therapy with Smiles | Medical |
| One stop Assessment Treatment Service | Medical |
| Osteochondral Autograft Transfer System | Medical |
| Osteochondral Autograft Transfer Surgery | Medical |
| Offering Alternative Therapy with Smiles | Medical |
| Over Armor Technology Synthesis | Military and Defence |
| Outside Agencies Tracing Service | Sports |
| Office Automation Technology and Services | Technology |
