F# is a functional-first programming language that runs on the .NET platform. It is designed to be concise, expressive, and efficient, making it suitable for a variety of applications, from web development to data analysis. F# supports both functional and object-oriented programming paradigms, allowing developers to choose the best approach for their projects. One of the key features of F# is its strong type inference, which reduces the need for explicit type declarations. This helps to catch errors at compile time, improving code reliability. F# is often used in conjunction with other languages in the Microsoft ecosystem, such as C# and Visual Basic.