OSI
OSI is best known as the reference model for network communication, yet the same letters also identify the open‑source software advocacy group, integration frameworks, a strategic think‑tank, and a historic video‑game company.
Miscellaneous
Oil Stability Index
Office Of Scientific Information
Open System Inter
The Overall Satisfaction Index
Open Solver Interface
Open Systems International
Ocean Star International
Open Systems Interconnect
Office of Systems Integration
Other Significant Information
Community
Governmental
A Organization For Standards Institute
Office Of Strategic Intelligence
Operational Subsystem Interface
Office of Special Investigations
Office Of Supernatural Investigation
Open Space Institute
Open Society Institute
Academic & Science
Open Systems Interconnection
Orchestra Of Strategic Influence
Ordinary Stuffed Isotopes
Office Of Special Investigation