ArchNEMESIS analyzes remote sensing spectroscopic observations of planetary atmospheres. It is based on the widely used NEMESIS (ascl:2210.009) radiative transfer and retrieval tool, which has been extensively used for the investigation of a wide variety of planetary environments.

NEMESISPY infers the atmospheric properties of exoplanets, such as chemical composition, using spectroscopic data. The package calculates radiative transfer using the correlated-k approximation and for parametric atmospheric modelling. NEMESISPY is a Python implementation of the well-established Fortran NEMESIS library (ascl:2210.009), which has been applied to the atmospheric retrievals of both solar system planets and exoplanets employing numerous different observing geometries.