Syphon Filter is a third-person shooter stealth video game series developed by Bend Studio (formerly Eidetic) and published by Sony Computer Entertainment (previously 989 Studios) In the series, Syphon filter is the name that is given to the mysterious biological weapon.
See also: Syphon Filter (video game), Syphon Filter 2, Syphon Filter 3, Syphon Filter: Logan's Shadow, Syphon Filter: Dark Mirror, and Syphon Filter: The Omega Strain.