Thanks to linux and its windows emulation layer, it is now possible to revisit the golden age of combat flight sims. This golden age started in 1998, when the ambitious combat flight sim/war game commercial products were released. It only lasted a few years, until it became clear that there wasn't a big enough market to profitably sell these complex sims.
For several more years, though, open source development continued thanks to community volunteers. The sprawling code bases, with patches buried in old internet forums and Windows 10 incompatibilities, were later abandoned.
Now thanks to linux/wine, you can download and run these old sims easily on linux
Three of the best old combat flight sims are available at the github page below. These sims are now free and open source.
https://github.com/sim-museum/esports-for-engineers