| COSMOS | C# Open-Source Managed Operating System 
| Others |
| COSMOS | Cluster Of Systems of Metadata for Official Statistics
| Others |
| COSMOS | Community-Oriented Science and Mathematics Opportunities For Students
| Others |
| COSMOS | Complete Online Solutions Manual Organization System
| Others |
| COSMOS | Computer System for Mainframe Operations
| Others |
| COSMOS | Consortium of Strong Motion Observation Systems
| Others |
| COSMOS | Consortium of Strong Motion Observations Systems
| Others |
| COSMOS | Cooperative Object Service Management for Open Systems
| Others |
| COSMOS | Counter Surge Mission Mortar System
| Others |
| COSMOS | Customer Operations Service Master On-line System
| Others |
| COSMOS | Customer Oriented Service Management And Operational System
| Others |