For fun, I wrote a CHIP8 interpreter in Fortran recently [1].

Fortran is still heavily used in computational chemistry, computational fluid dynamics, marine engineering, nuclear engineering, reservoir engineering, and numerous other engineering fields. Volcanologists use it to predict ash dispersal [2]. Biomedical companies use it for cardiac electrophysiology. Econometrists use it to do tax research [4]. Plasma physicists use it to design magnetic confinement fusion devices [5]. Astrophysicists use it for relativistic magnetohydrodynamics [6]. NASA uses it for all kinds of fluid dynamics-related purposes [7] (read jet engines and rockets), and so do they at CERFACS [8]. For all I know, some integrated circuit manufacturers probably use it use it [9]. It's also used in ham radio and probably some military agencies [10]. It's used in vehicle crash testing [11]. It's used in combustion simulation software [12], fire dynamics [13], hydrometallurgy (ore leaching) [14]. US Geological Survey uses it for ground-water flow modelling [15]. We could go on and on.

[1] https://news.ycombinator.com/item?id=38920486 [2] https://doi.org/10.1016/j.cageo.2008.08.008 [3] https://www.elem.bio/index.html [4] https://taxsim.nber.org/ [5] https://doi.org/10.1016/j.cpc.2021.107986 [6] https://doi.org/10.3390/fluids9010016 [7] https://fun3d.larc.nasa.gov/ [8] https://www.cerfacs.fr/avbp7x/ [9] https://en.wikipedia.org/wiki/SPICE [10] https://en.wikipedia.org/wiki/Numerical_Electromagnetics_Cod... [11] https://www.openradioss.org/ [12] https://en.wikipedia.org/wiki/CHEMKIN [13] https://en.wikipedia.org/wiki/Fire_Dynamics_Simulator [14] https://youtu.be/-dvG270QttE?si=AO-ky0fGwkIEmXDx [15] https://www.usgs.gov/mission-areas/water-resources/science/m...