CORSIKA is a detailed Monte Carlo program for simulating extensive air showers (EAS) initiated by high-energy cosmic rays. It tracks particles through the atmosphere, simulating their interactions, decays, and electromagnetic processes. The program uses various models for hadronic interactions, including VENUS, QGSJET, DPMJET, SIBYLL, and HDPM, as well as electromagnetic interactions via EGS4 or NKG formulas. CORSIKA allows for the simulation of particle decays, Cherenkov radiation, and neutrino production. It is used by multiple research groups to study cosmic rays and their secondaries at high energies. The program includes detailed particle tracking, mean free path calculations, and options for thin sampling to reduce computational time. CORSIKA is continuously updated and available for use, with documentation and data sets provided for simulation. The program is designed to accurately predict both average values and fluctuations in EAS simulations, making it a valuable tool for high-energy physics research.CORSIKA is a detailed Monte Carlo program for simulating extensive air showers (EAS) initiated by high-energy cosmic rays. It tracks particles through the atmosphere, simulating their interactions, decays, and electromagnetic processes. The program uses various models for hadronic interactions, including VENUS, QGSJET, DPMJET, SIBYLL, and HDPM, as well as electromagnetic interactions via EGS4 or NKG formulas. CORSIKA allows for the simulation of particle decays, Cherenkov radiation, and neutrino production. It is used by multiple research groups to study cosmic rays and their secondaries at high energies. The program includes detailed particle tracking, mean free path calculations, and options for thin sampling to reduce computational time. CORSIKA is continuously updated and available for use, with documentation and data sets provided for simulation. The program is designed to accurately predict both average values and fluctuations in EAS simulations, making it a valuable tool for high-energy physics research.