F# vs ATS

F#'s syntax tends to be terse while remaining very readable and easy to understand without being a chore to write.

Since F# is not a purely functional language, it lends itself to being more easily picked up by programmers that have experience with other paradigms.

Since F# runs on the Common Language Runtime or CLR, it has access to the entire .NET Framework, as well as libraries written in other .NET languages such as C#, VB.NET, and C++/CLI.

Forget Xamarin and Mono. F# now runs on the multiplatform .Net Core!

Thanks to a project like Fable, you can write and run your client app in F# and run it over JavaScript. It allows you to share code between your server and client.

This is a .Net language natively supported by Visual Studio. Though it is not as tooled up as C# the support is still substantial. In particular, C# deployment scenarios can be enabled for it with small C# wrapper projects. Integration with Visual Studio provides: IntelliSense, debugging, projects an other features.

F# directs you into a workflow where the right way is the path of least resistance.

Coming from a C# background, its restrictions might feel arbitrary at first (e.g., what do you mean my code has to be in dependency order!? Arbitrary alphabetical or bust!), but you'll soon realize that your code is cohesive, concise and consistent in a way that it never was before - and you can compile and run with confidence!

Thanks to Xamarin, F# is a functional language that you can use to build for iOS, Android and Windows.

ATS has a theorem-proving type system powerful enough to prove that its functions meet their specifications. This happens at compile time with no performance impact at runtime. This can be used to prove that an ATS program doesn't have bugs commonly found in C++ programs, like "this function never leaks memory" or "this program never attempts to divide by zero" or "this buffer never overflows" or to verify pointer arithmetic, etc.

The compiler (ATS/Postiats) is GPLv3.

The syntax is ML-like with the usual functional language features like pattern matching and tail-call optimization.

ATS works as a low-level systems language. ATS programs have performance and footprint comparable to programs written in C/C++.

Similar to Modula-3. This makes ATS a viable choice even for large-scale projects.

ATS can prove its concurrent programs have no deadlocks or race conditions.