PRG can mean: Parti radical de gauche (Radical Party of the Left), France Paul Roos Gymnasium, school in Stellenbosch, South Africa Post/Redirect/Get, in web applications prg, ISO 639-3 language code for the Old Prussian language Václav Havel Airport Prague, IATA code Programming Research Group, Oxford University 1965-2011 Provisional Revolutionary Government of the Republic of South Vietnam, Viet Cong party People's Revolutionary Government (Grenada) Pseudorandom generator, of deterministic but pseudorandom numbers .prg is a file format used for Commodore 64 software Pontificale Romano-Germanicum, set of Latin documents of Catholic liturgical practice compiled in Saint Alban's Abbey, Mainz, in the 10th century.