This is the approved USGS MODFLOW 6.5.0 release.
Langevin, C.D., Hughes, J.D., Provost, A.M., Russcher, M.J., Morway, E.D., Reno, M.J., Bonelli, W.P., Panday, Sorab, Merrick, Damian, Niswonger, R.G., Boyce, S.E., and Banta, E.R., 2024, MODFLOW 6 Modular Hydrologic Model version 6.5.0: U.S. Geological Survey Software Release, 23 May 2024,
https://doi.org/10.5066/P13COJJM
Visit the USGS "MODFLOW and Related Programs" site for information on MODFLOW 6 and related software: https://doi.org/10.5066/F76Q1VQV