The Weather Research and Forecasting Model (WRF) software projects represent sound examples of how citable resources can be made from widely used software.
WRF-ARW - Weather Research and Forecasting Model - Advanced Research WRF
This project provides a simple citation example:
WRF Community. (2000). Weather Research and Forecasting Model. 126.96.36.199. UCAR/NCAR. https://doi.org/10.5065/D6MK6B4K. Accessed 22 December 2021.
The WRF-Hydro software, which is a hydrological extension to the WRF model provides a citation recommendedation like this:
Gochis, David J., Barlage, Michael, Cabell, Ryan, Casali, Matthew, Dugger, Aubrey, FitzGerald, Katelyn, McAllister, Molly, McCreight, James, RafieeiNasab, Arezoo, Read, Laura, Sampson, Kevin, Yates, David, Zhang, Ying. (2013). WRF-Hydro Modeling System. 5.0. UCAR/NCAR - Research Application Laboratory. https://doi.org/10.5065/d6j38rbj. Accessed 22 December 2021.