The code was initially derived from STEM (G.R. Carmichael et al., Centre for Global and Regional Environmental Research, Univ. of Iowa)

Major contributions have come from:

• ARIANET, also coordinating code development
• ENEA – Atmospheric Pollution Laboratory, initially/also through MINNI project (sponsored by Italian Ministry for the Environment, Land and Sea)
• ARPA Lazio, fostering the development of the data assimilation module
• ARPA Piemonte, sponsoring full parallelization through CINECA supercomputing center