| OntoUCP | Ontology-based Unified Communication Protocol | In English | → Programming languages |
| OOMM | Organizational Operations and Maintenance Manual | In English | → Maintenance and logistics |
| OP | Operating Procedure | In English | → Management |
| OP&R | Operations Planning and Requirements | In English | → Management |
| OPA | Operations Planning Analysis | In English | → Management |
| OPC | Open Process Control | In English | → Management |
| OPECST | Office Parlementaire d'Évaluation des Choix Scientifiques et Technologiques | In French | → Research policy → Politics → Engineering, technology |
| OPI | Ośrodek Przetwarzania Informacji (www.opi.org.pl) | In Polish | → Research policy |
| OPI | Operations Procedure Instruction | In English | → Management |
| OPIDF | Operational Planning Identification File | In English | → Management |
| OPM | Operations Procedure Manual | In English | → Management |
| OPML | Outline Processor Markup Language | In English | → Programming languages |
| OPPS | Operations Planning and Project Support | In English | → Management |
| OPPTIC | Organisation de Professionnels pour la Promotion des TIC en région Languedoc-Roussillon | In French | → Networks, communication → Organizations and associations → Telecommunications |
| OPR | Operations Planning Review | In English | → Management |
| OPR | Office of Primary Responsibility | In English | → Management |
| OPS | Operational Sequence | In English | → Management |
| OPSDB | Operations Data Base | In English | → Data |
| OPSDBA | Operations Data Base Administrator | In English | → Data → Management |
| OPSIS | Observation et Prospective sur la Société de l'Information et ses Services | In French | → Computer science → Telecommunications |
| ORA | Operational Requirements Analysis | In English | → Management |
| ORAM | Output Random Access Memory | In English | → Memories |
| ORAP | Organisation Associative du Parallélisme | In French | → Computer science → Organizations and associations |
| ORB | Object Request Broker | In English | → Networks, communication |
| ORB | Operations Review Board | In English | → Management |
| ORC | Optical Character Recognition = ROC | Reconnaissance Optique de Caractères | In French |
In English | → Writing systems → Computer-based techniques |
| ORCHIS | Oak Ridge Computerized Hierarchical Information System | In English | → Computer science → Knowledge management |
| ORD | Operations Requirements Document | In English | → Management |
| ORDI | Ontology Representation and Data Integration | In English | → Software |
| ORI | Operational Readiness Inspection | In English | → Management |
| ORIENT | Oriental Research Infrastructure to European Networks | In English | → Research policy → International relations |
| ORLA | Optimum Repair Level Analysis | In English | → Maintenance and logistics |
| ORR | Operations Requirements Review | In English | → Management |
| ORR | Operational Readiness Review | In English | → Management |
| ORRCA | Ontario Research Centre for Computer Algebra | In English | → Computer-based techniques → Algebra |
| ORSDI | Oak Ridge Selective Dissemination of Information | In English | → Computer science → Knowledge management |
| ORT | Operational Readiness Test | In English | → Management |
| OS | Operating Software | In English | → Software |
| OS | Operating System | In English | → Operating systems |
| OS3B | Open Software Blanc Bleu Belge | In French | → Organizations and associations → Software |
| OSCF | Operations Support Computing Facility | In English | → Computer science |
| OSCR | Orbiter Software Change Request | In English | → Software → Spaceflight engineering, astronautics |
| OSCRS | Orbital Spacecraft Consumables Resupply System | In English | → Maintenance and logistics → Spaceflight engineering, astronautics |
| OSDL | Open Source Development Labs | In English | → Software |
| OSDL | Open Source Development Lab | In English | → Software |
| OSE | Open System Environment | In English | → Computer science |
| OSERA | Ohio Scientific Education & Research Association (www.osera.org) | In English | → Associations → Research policy → Education |
| OSF | Open Software Foundation | In English | → Foundations → Software |
| OSI | Open Source Initiative | In English | → Software |
| OSID | Operating System Interface Definition | In English | → Operating systems → Human-computer interaction |
| OSIM | Open Source In Morocco | In English | → Organizations and associations → Software |
| OSM | Operational Status Monitoring | In English | → Management |
| OSMP | Operational Support Maintenance Plan | In English | → Maintenance and logistics |
| OSPF | Open Shortest Path First | In English | → Internet |
| OSRBD | Operational Software Reliability Benchmark Development | In English | → Software |
| OSTDS | Office of Space Tracking and Data Systems | In English | → Data → Spaceflight engineering, astronautics |
| OSTP | Office of Science and Technology Policy | In English | → Research policy → Engineering, technology |
| OTDA | Office of Tracking And Data Acquisition | In English | → Data |
| OVI | Operational Validation Inspection | In English | → Management → Engineering, technology |
| ÖWiG | Österreischische Wissenschaftsgesellschaft (www.oewig.at) | In German | → Organizations and associations → Research policy |
| OWL | Web Ontology Language | In English | → Data → Programming languages |
| P&D | Panels and Displays | In English | → Human-computer interaction |
| P&D | Pesquisa e Desenvolvimento = R&D | Recherche et développement | In French = F&E | Forschung und Entwicklung | In German = R&D | Research and Development | In English = I+D | Investigación y Desarrollo | In Spanish = R&S | Ricerca e Sviluppo | In Italian = O&O | Onderzoek en Ontwikkeling | In Dutch = FoU | Forsøk og Utvikling | In Norwegian |
In Portuguese | → Research policy → Engineering, technology |
| P&I | Performance and Interface | In English | → Human-computer interaction |
| P&M | Production and Maintenance | In English | → Maintenance and logistics |
| P&MD | Productivity and Manufacturing Development | In English | → Maintenance and logistics |
| P&P | Policies and Procedures | In English | → Management |
| P&PQ | Productivity and Product Quality | In English | → Quality management |
| P&PQI | Productivity and Product Quality Improvement | In English | → Quality management |
| P&PQIC | Productivity and Product Quality Improvement Council | In English | → Quality management |
| P&Q | Productivity and Quality | In English | → Quality management |
| P&R | Performance and Resources | In English | → Maintenance and logistics |
| P2I | Preplanned Productivity Increase | In English | → Management |
| P2IC | Programme Interne aux Instituts Carnot | In French | → Research policy |
| P2P | Peer-to-Peer | In English | → Networks, communication |
| P3I | Preplanned Product Improvement | In English | → Management |
| P3I | Preplanned Production Improvement | In English | → Management |
| P3P | Platform for Privacy Preferences | In English | → Networks, communication → Telecommunications |
| PADSIM | Probabilistic Adaptive Simulation Model | In English | → Computer simulation |
| PAI | Public Authority for Industry | In English | → Standardization → Public administration, government |
| PAIR | Portal to Asian Internet Resources | In English | → Libraries → Networks, communication |
| PAMI | Pattern Analysis and Machine Intelligence | In English | → Document processing |
| PAPG | Plan d'Amélioration de la Productivité Globale | In French | → Management |
| PAQ | Plan d’Assurance Qualité | In French | → Quality management |
| ParC | Parallel Computing | In English | → Serial publications, periodicals → Computer science |
| PaReL | Pattern Recognition Letters | In English | → Serial publications, periodicals → Computer-based techniques |
| PASC | Pacific Area Standards Congress | In English | → Congresses → Standardization |
| PASO | Pattern-Oriented Software Architecture | In English | → Software |
| PASOLS | Pacific Area Senior Officer Logistics Seminar | In English | → Maintenance and logistics |
| PASS | Primary Avionics Software System | In English | → Software → Aeronautics, aircraft |
| PASTEL | Plateforme d’Assistance Technique Européenne en Lorraine | In French | → Research policy → Regional administration |
| PASTISS | Professional Analysis Software Tool for Inflatable Space Structures | In English | → Software → Mechanical engineering |
| PauLLA | Pau Logiciels Libres Association | In French | → Associations → Software → Operating systems |
| PBB | Provider Backbone Bridge | In English | → Networks, communication → Telecommunications |
| PBB-TE | Provider Backbone Bridge - Traffic Engineering | In English | → Networks, communication → Telecommunications |
| PBBN | Provider Backbone Bridge Network | In English | → Networks, communication → Telecommunications |
| PBEB | Provider Backbone Edge Bridge | In English | → Networks, communication → Telecommunications |
| PBIC | Programmable Buffer Interface Card | In English | → Hardware → Software |
| PBIM | Programmable Buffer Interface Module | In English | → Software → Human-computer interaction |
| PBM | Program Business Management | In English | → Management |
| PBS | Portable Batch System | In English | → Software → Networks, communication |
| PBT | Provider Backbone Transport | In English | → Networks, communication → Telecommunications |
| PC | Personal Computer = PK | Persoanlike kompjûter | In Frisian |
In English | → Hardware |
| PC | Programming Committee | In English | → Management |
| PC&PM | Program Control and Performance Management | In English | → Software |
| PCA | Programme Commun d'Activités | In French | → Management |
| PCA | Popular Culture Association | In English | → Associations → Civilization, culture, progress |
| PCBC | Polskie Centrum Badań i Certyfikacji | In Polish | → Standardization |
| PCDATA | Parsed Character Data | In English | → Data |
| PCGI | Perl Common Gateway Interface | In English | → Programming languages → Networks, communication |
| PCI | Peripheral Component Interconnect | In English | → Hardware → Telecommunications |
| PCI | Peripheral Controller Interface | In English | → Human-computer interaction |
| PCI-E | Peripheral Component Interconnect Express | In English | → Computer science → Electronics |
| PCL | Programming Checklist | In English | → Software |
| PCM | Pulse Code Modulation | In English | → Computer-based techniques → Music |
| PCMCIA | Personal Computer Memory Card International Association | In English | → Associations → Memories |
| PCMU | Programmable Control and Monitor Unit | In English | → Computer science |
| PCP | Project Cost Plan | In English | → Management → Prices |
| PCP | Program/Project Change Proposal | In English | → Management |
| PCR | Project Control Room | In English | → Management |
| PCR | Program Change Request | In English | → Management |
| PCR | Procedure Change Request | In English | → Management |
| PCRD | Programme-Cadre de Recherche et de Développement | In French | → Research policy → Engineering, technology |
| PCRE | Perl-Compatible Regular Expression | In English | → Software |
| PCS | Program Control System | In English | → Management |
| PCS | Performance Control System | In English | → Management |
| PCS | Project Control System | In English | → Management |
| PCS | Planning and Control System | In English | → Management |
| PCS | Professional Clinical Software | In English | → Software → Medicine |
| PCSI | Projet de Coopération Scientifique Inter-universitaire | In French | → Research policy → Higher education, universities |
| PCTR | Protocol Conformance Test Report | In English | → Standardization |
| PDA | Personal Digital Assistant | In English | → Hardware → Telecommunications |
| PDAR | Program Description and Requirements | In English | → Management |
| PDB | Project Development Brochure | In English | → Management |
| PDCA | Plan, Do, Check, Act | In English | → Quality management |
| PDD | Program Description Document | In English | → Management |
| PDD | Program Definition Document | In English | → Management |
| PDES | Product Data Exchange Specification/Standard | In English | → Standardization → Trade |
| Portable Document Format | In English | → Programming languages → Data → Document processing |
|
| PDH | Plesiochronous Digital Hierarchy | In English | → Networks, communication → Telecommunications |
| PDM | Product Data Management | In French | → Management |
| PDM | Processor Data Monitor | In English | → Human-computer interaction → Data |
| PDP | Project Definition Phase | In English | → Management |
| PDP | Program Development Plan | In English | → Management |
| PDR | Program Design Review | In English | → Management |
| PDU | Protocol Data Unit | In English | → Networks, communication |
| PE | Parity Error | In English | → Computer science |
| PEB | Performance Evaluation Board | In English | → Management |
| PEC | Proposal Evaluation Criteria | In English | → Management |
| PEGASUS | Preliminary Expert Ground Analysis Scheduler | In English | → Management |
| PEM | Plant Engineering and Maintenance | In English | → Maintenance and logistics |
| PEP | Proposal Evaluation Panel | In English | → Management |
| PEP | Plant Engineering Procedure | In English | → Maintenance and logistics |
| PER | Preliminary Engineering Report | In English | → Management → Engineering, technology |
| PERL | Practical Extraction and Report Language | In English | → Programming languages |
| PERM | Programmgesteuerte Elektronische Rechenanlage | In German | → Hardware |
| PERT | Program Evaluation Research Task | In English | → Research policy |
| PERT | Program Evaluation and Review Technique | In English | → Management → Engineering, technology |
| PESSL | Parallel Engineering and Scientific Subroutine Library | In English | → Programming languages → Mathematics and natural sciences → Engineering, technology |
| PET | Performance Enhancement Team | In English | → Management |
| PET | Personal Electronic Transactor | In English | → Hardware |
| PET | Persona-Enabling Toolkit | In English | → Networks, communication → Telecommunications |
| PETSCII | PET Standard Code of Information Interchange | In English | → Computer science |
| PFS | Primary Flight Software | In English | → Software → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| PGC | Progiciel de Gestion du Contenu | In French | → Software → Knowledge management |
| PGI | Progiciel de Gestion Intégrée | In English | → Software |
| PGML | Precision Graphics Markup Language | In English | → Programming languages → Image processing |
| PGSC | Payload and General-Support Computer | In English | → Hardware |
| PHAROS | Platform for searcH of Audiovisual Resources across Online Spaces (www.pharos-audiovisual-search.eu) | In English | → Networks, communication → Computer-based techniques |
| PHB | Per Hop Behavior | In English | → Networks, communication → Telecommunications |
| PHP | PHP Hypertext Preprocessor | In English | → Programming languages → Networks, communication |
| PHP | Personal Home Page | In English | → Programming languages → Networks, communication |
| PHRC | Programme Hospitalier de Recherche Clinique | In French | → Research policy → Medicine |
| PHST | Packaging, Handling, Storage, and Transportation | In English | → Maintenance and logistics → Transport and postal services |
| PHTR | Packaging, Handling, and Transportation Record | In English | → Maintenance and logistics → Transport and postal services |
| PI&A | Personnel Identification and Authentication | In English | → 00495 → Labour, labour economics |
| PIC | Performance Indicator Chart | In English | → Management |
| PIC | Process Information Cockpit | In English | → Knowledge management |
| PICC | Payload Interface Control Computer | In English | → Hardware → 0055 |
| PICP | Program Interface Control Plan | In English | → Human-computer interaction |
| PICS | Platform for Internet Content Selection | In English | → Internet |
| PIDS | Portable Image Display System | In English | → Human-computer interaction |
| PIIT | Parque de Investigación e Innovación Tecnológica | In Spanish | → Research policy → Engineering, technology |
| PIM | Planning Interchange Meeting | In English | → Management |
| PIMR | Program Integration Management Review | In English | → Management |
| PIN | Personal Identification Number | In English | → Personnel management → Labour, labour economics |
| PINCH | Payload Integration Nominal Cost Hardware | In English | → Hardware |
| PING | Packet Internet Gopher | In English | → Networks, communication |
| PIP | Personnel Incentive Program | In English | → Labour, labour economics → Personnel management |
| PIP | Project Implementation Plan | In English | → Management |
| PIRN | Proposed Interface Revision Notice | In English | → Human-computer interaction |
| PIRN | Preliminary Interface Revision Notice | In English | → Human-computer interaction |
| PK | Persona Komputilo | In Esperanto | → Hardware |
| PK | Persoanlike kompjûter = PC (look above) |
In Frisian | → Hardware |
| PKD | Programmable Keyboard and Display | In English | → Human-computer interaction |
| PKI | Public Key Infrastructure | In English | → Computer science |
| PKN | Polski Komitet Normalizacyjny | In Polish | → Standardization |
| PLA | Programmable Logic Array | In English | → Hardware → Electronics |
| PLD | Programmable Logic Device | In English | → Hardware → Electronics |
| PLDI | Programming Language Design and Implementation | In English | → Programming languages |
|