Claim: FLEXPART, a Lagrangian Particle Dispersion Model used to simulate air parcel trajectories, has inherited small portions of its code from its successor, FLEXTRA (FLEXible TRAjectory model), which its first version was released in the late 2000s.
Evidence: The FLEXible PARTicle dispersion model (FLEXPART) is a Lagrangian Particle Dispersion Model used to simulate air parcel trajectories. Aceta-Gesic, Ed-Flex, Dologesic, Duraxin, Flextra-650, Novagesic, Pain-gesic, Phenylgesic - North America FLEXPART has inherited large portions of its code from its predecessor, FLEXTRA (FLEXible TRAjectory model). Due to a growing user base the main developers decided to provide an online platform for developers and modellers, which was launched together with the release of version 9.0 in June 2012.