| Company name | Category |  | 
              
                | Objective Interface Systems | Embedded software and operating systems |  | 
              
                | OBSAI | Recruitment, reports, resources |  | 
              
                | Ocean Blue | Embedded software and operating systems |  | 
              
                | Ocean Optics | Stand-alone instruments |  | 
              
                | Octagon Systems | Embedded computing and control |  | 
              
                | Octasic | Communications ICs (wired) |  | 
              
                | Octo Media | Exhibitions, courses, conferences, training |  | 
              
                | Octware | Embedded software and operating systems |  | 
              
                | ODU | Plugs and sockets |  | 
              
                | OEM Automatic | Fans and blowers |  | 
              
                | OFS | Optical fibres, cables, connectors |  | 
              
                | OFS Specialty Photonics | Optical fibres, cables, connectors |  | 
              
                | OGP | Test and measurement |  | 
              
                | Ohmite | Resistors |  | 
              
                | OK International | PCB assembly equipment, tools |  | 
              
                | Oki Electric | Microprocessors, microcontrollers and DSPs |  | 
              
                | OLC | Fans and blowers |  | 
              
                | OLED-T | Light-emitting diodes (LEDs) |  | 
              
                | Olympus Industrial | Electronics manufacturing materials |  | 
              
                | Omeg | Rotary controls, joysticks etc |  | 
              
                | Omega Engineering | Stand-alone instruments |  | 
              
                | Omega Research | Interconnection |  | 
              
                | Ommic | Analogue and mixed-signal ICs |  | 
              
                | Omnetics Connector | Plugs and sockets |  | 
              
                | Omniflex | Power supplies |  | 
              
                | Omnivision | Optoelectronic sensors, switches, receivers |  | 
              
                | Omnivision Technologies | Sensors and data acquisition |  | 
              
                | Omron | Other OEM display modules, meters |  | 
              
                | Omron AOI | Electronics manufacturing materials |  | 
              
                | Omron Electronics | Electromechanical components |  | 
              
                | Omron Scientific Technologies | Sensors and data acquisition |  | 
              
                | On 365 | UPSs |  | 
              
                | ON Semiconductor | Power-supply ICs and controllers |  | 
              
                | Onanon | Plugs and sockets |  | 
              
                | Onboard Electronics | EMC components |  | 
              
                | Ondax | Lasers |  | 
              
                | One Media | Intellectual property cores |  | 
              
                | One RF Technology | Wireless communications |  | 
              
                | Oneac | Circuit protection devices |  | 
              
                | Onespin Solutions | Design and development software |  | 
              
                | Opal | Microprocessors, microcontrollers and DSPs |  | 
              
                | Opal Kelly | Design and development hardware |  | 
              
                | Open Interface | Design and development software |  | 
              
                | Open Systems Publishing | Recruitment, reports, resources |  | 
              
                | Open-Plug | Design and development software |  | 
              
                | Opencores | Communications ICs (wired) |  | 
              
                | Openxtra | Cables and wires |  | 
              
                | Ophir RF | Stand-alone instruments |  | 
              
                | Ophir-Spiricon | Opto and fibre test equipment |  | 
              
                | Opsitech | Optical filters, lenses, gratings |  | 
              
                | Optek Technology | Light-emitting diodes (LEDs) |  | 
              
                | Opti-Ups | UPSs |  | 
              
                | Optical Antenna Solutions | Optical filters, lenses, gratings |  | 
              
                | Optical Surfaces | Optoelectronics |  | 
              
                | Opto Diode | Optoelectronic sensors, switches, receivers |  | 
              
                | Opto Technology | Light-emitting diodes (LEDs) |  | 
              
                | Optoelectronic Manufacturing | Other OEM display modules, meters |  | 
              
                | Optotherm | Electronics manufacturing quality assurance |  | 
              
                | Optrex | Touchscreens and touch sensors |  | 
              
                | Opulan Technologies | Communications ICs (wired) |  | 
              
                | Oracle Components | Electronics manufacturing materials |  | 
              
                | Orange Tree Technologies | PC-compatible boards, assemblies |  | 
              
                | Orchid Technologies Engineering and Consulting | Design services |  | 
              
                | Organic Electronics Association | Exhibitions, courses, conferences, training |  | 
              
                | Oriental Motor | Fans and blowers |  | 
              
                | Orion Fans | Fans and blowers |  | 
              
                | Orlin Technologies | Electronics manufacturing materials |  | 
              
                | Orlin Technology | Design and development hardware |  | 
              
                | Orolia | Frequency control components |  | 
              
                | OSA Opto Light | Optoelectronics |  | 
              
                | OSA Technologies | Embedded software and operating systems |  | 
              
                | Osram Opto Semiconductors | Light-emitting diodes (LEDs) |  | 
              
                | Osram Sylvania | Industry news |  | 
              
                | Ovation Products | Electronics manufacturing materials |  | 
              
                | Ove Arup and Partners | Design and development software |  | 
              
                | Owasys Advanced Wireless Devices | Wireless communications |  | 
              
                | Owens Design | Test accessories |  | 
              
                | Oxford Instruments Industrial Analysis | Electronics manufacturing materials |  | 
              
                | Oxford Instruments Plasma Technology | IC and hybrid processing equipment |  | 
              
                | Oxford Lasers | IC and hybrid processing equipment |  | 
              
                | Oxford Nanoscience | Electronics manufacturing materials |  | 
              
                | Oxford Semiconductor | Communications ICs (wired) |  | 
              
                | Ozmo Devices | Communications ICs (wireless) |  |