PSO

PSO stands for:

Particle swarm optimization, an optimization algorithm based on swarm intelligence
Pakistan State Oil , a Pakistani petroleum company, see List of Petroleum Companies #Alphabetic List of Companies
Parliamentary Forum of the Southern Baltic Sea , a forum for the regional representative bodies of several Baltic Sea countries

Peace Support Operation , military and civilian measures to secure or restore peace

Phantasy Star Online , a multiplayer role-playing game from Sega for game consoles and PCs

Process standard offset , industrial and standardized production of printed matter

Penalty Shoot Out, penalty shootout in football

PSO-1 , a rifle scope of Soviet origin

pso stands for: