| Operation Antler | Open sandwich | Operation Enduring Freedom - Philippines |
| Operation Medak pocketOperation Medak Pocket ( Croatian: Medacki dzep was a military operation undertaken by the Croatian army between September 9 — September 17, 1993 in which the small area around the village of Medak in the south-central Lika region of Croatia, then under t | Operation Noble EagleOperation Noble Eagle is the US military operational designator refers to the military's efforts in the War on Terrorism that were carried out on US soil. The operation began September 15, 2001, in response to the September 11 terrorist attacks, and conti | Operation Sea DragonFollowing the Tonkin Gulf Incident US Naval forces in Vietnam were assigned to four major duties Operation Sea Dragon Operation Market Time, Operation Sealords and Naval Gunfire Support. The primary purpose of Sea Dragon forces was the interception and de |
| Operational display systemOperational Display Systems in avionics, refers to systems used for tracking the status of multiple objects. Operational Displays Systems are usually being developed by large countries' Civil Aviation Authorities (such as the FAA in the USA, or Eurocontro | OpenAFSOpenAFS is an open source implementation of the Andrew file system (AFS). AFS was originally developed at CMU, and developed as a commercial product by the Transarc Corporation, which was subsequenly acquired by IBM. At LinuxWorld on 15 August 2000, IBM a | Operation RockinghamOperation Rockingham is an intelligence unit whose existence was revealed in June 2003 by the Scottish Sunday Herald. Based mainly on an interview with former US military intelligence officer and chief UN weapons inspector Scott Ritter, investigative jour |
| Operator algebraIn functional analysis, an operator algebra is an algebra of continuous linear operators on a topological vector space (such as a Banach space), which is typically required to be closed in a specified operator topology. In particular, it is a set of opera | Operator associativitySee: Associativity Order of operations (informal description) Common operator notation (more formal, but still informal description). | Operation JedburghJedburgh was an operation in World War II in which men from the Office of Strategic Services parachuted into Nazi occupied France to conduct sabotage and guerilla warfare, and to lead French maquis forces against the Germans. The operation took its name f |
| Open Financial Exchange | Oprichnik | Operation Grenade |
| Opto-isolator | OPAC | OperServ |
| Opsound | Operation Arc Light | Opinion leadership |
| Open Services Architecture | OPS5 | Operation Bagration |
| Operation Slapstick | Operation Cobra | Open Mike with Mike Bullard |
| Opera Bastille | Opéra National de Paris | Open source journalism |
| Opera Company of Boston | Openness | Operation Athena |
| Opera Boston | Open Document Architecture | Opening credits |
| Optus Television | Operation Infinite Reach | Open University of Sri Lanka |
| Operation Michael | Ophioglossophyta | Operation Agreement |
| Opening | OpenGroupware.org | OpenCores |
| Opioid | Open | OPC |
| Optically Stimulated Luminescence | Operation Battleaxe | Operation Crusader |
| OpenFTS | Operation Castle | Open Door Policy |
| Opthalmoplegia | Operation Market Time | Operation Power Pack |
| Operation Antler (Porton Down investigation) | Opportunistic infection | OPSM |
| Operation Uphold Democracy | Operation Restore Hope | Operation Herkules |
| Op-Ed | Operation Plunder | Opisthokont |
| Opéra-Comique | Operation Corona | Open communion |
| Opera Software | Opéra National de Lyon | Opéra de Monte-Carlo |
| OpenC Plus Plus | OpenJava | Open University of Israel |
| Open shell | Optician | Operation Halo |
| Open Space Technology | OPL | Operation Horseshoe |
| Operation Agatha | Opisthobranchia | Operation Grün (Ireland) |
| Optimize (magazine) | Open Bioinformatics Foundation | OpenAL |
| Open-loop controller | Operation Mobilisation | Open Canada Cup |
| Open list | Operation Pedestal | Operator (biology) |
| Operation Anthropoid | Operation Margarethe | Operation Cerberus |
| Operation Assistance | Operation Harmony | OpenMosix |
| OpenLP | Operation Mockingbird | Optical coating |
| Operators in C and C Plus Plus | Openbill stork | Opus Dei (album) |
