Fsharp

F# is a statically-typed, functional-first programming language on the .NET platform. It combines functional programming with support for object-oriented and imperative programming, enabling concise, expressive code while preserving interoperability with other .NET languages. Code is compiled to .NET assemblies and runs on the Common Language Runtime (CLR) or modern .NET runtimes such as .NET Core and .NET 5+. F# emphasizes immutability by default, strong type inference, and a concise syntax. Core features include pattern matching, discriminated unions, records, tuples, lists, arrays, options and results, units of measure, and type providers for typed access to external data sources. Computation expressions provide a syntax for asynchronous workflows and other computational patterns. F# also includes modules and a robust module system for organizing code.

History and status: F# was designed by Don Syme at Microsoft Research and first released in 2005. It was opened to the community in the late 2000s, and development today is driven by a combination of the F# Software Foundation, Microsoft, and community contributors. The language runs on modern .NET runtimes and supports cross-platform development on Windows, Linux, and macOS through the .NET platform.

Tooling and ecosystem: F# Interactive (fsi) supports scripting and exploration, while the FSharp.Core library provides core functionality. Build and package management are handled via the dotnet CLI and NuGet packages. Popular IDEs and editors include Visual Studio, Visual Studio Code with the Ionide extension, and JetBrains Rider. The ecosystem includes data-science and web-related libraries such as Deedle, FSharp.Data, Giraffe, and Saturn, among others.

Usage: F# is commonly employed in financial modeling, data analysis, scientific computing, and rapid prototyping. It is valued for expressiveness, safety, and concise code, though its ecosystem is smaller than that of C#. It remains an active language within the .NET community.