Not underrated, but F# gets a lot of flack for what has proven an extremely usable and productive language. * It is functional and succinct by default, but all

Not underrated, but F# gets a lot of flack for what has proven an extremely usable and productive language. * It is functional and succinct by default, but allows you to go mutable and fast when needed (see the alioth benchmarks). * Open source culture * The tooling (thanks to kcieslak and others) is fantastic * Web story is covered well by suave/giraffe on the backend, with fable-elmish as a personal favorite if I need complex front-end functionality (most stuff I have is just regular pages though). * Mobile story through Xamarin(Forms is not my favorite, but Native works fine) or Fable * To mention javascript again, I think Fable has a ton of well thought out features compared to other transpiled languages * Testing via expecto (and just github.com/haf in general) * A whole wealth of libraries through .net integration * I can compile a binary to execute on linux for easy deployments, or target osx to create convenience command line applications for my coworkers There are some negatives (some C# interop gets inelegant, some tooling is left to the community as a responsibility, other minor things), but overall it has all of the important things.