| Eckerd College Organization of Students | Academic & Science |
| Environmentally Conscious Organization of Students | Academic & Science |
| Emerald Cove Outdoor Science | Academic & Science |
| Environmentally Concerned Organization of Students | Academic & Science |
| Environmental Coordination Office Of Students | Academic & Science |
| Educator Certification Online System | Business |
| ECOS Group, Incorporated (de-listed) | Business |
| Efficiency Costs Optimization Simulation | Business |
| Environment Community Opportunity and Sustainability | Community |
| Environment Community Opportunity Sustainability | Community |
| Every Community Offering Service | Community |
| Events for Communities Of Sustainability | Community |
| Experimental Computer Operational Software | Computing |
| Extended Communications Operating System | Computing |
| EcoDollar | Cryptocurrency |
| Electronic Check-Out System | General |
| Employee Car Ownership Schemes | General |
| Engine Cut Off Switch | General |
| Efficient Cabin Open Space | General |
| Embedded Cygnus Operating System | General |
| Environmental Council of the States | Governmental |
| Environmental Conservation Online System | Governmental |
| Environmental Council of Sacramento | Governmental |
| Examinations Council Of Swaziland | Governmental |
| Embedded Configurable Operating System | Information Technology |
| Education and Career Opportunities System | Jobs |
| European Coalition on Oil in Sudan | Regional |
| East County One Stop | Regional |
| Experiment Computer Operating System | Space Science |
| Electronic Customised Option System | Stock Exchange |
