An F# Script file (fsscript) is a source code file used by the F# programming language, which is a functional-first, multi-paradigm language that runs on the .NET platform. Unlike standard F# source files (.fs) that are typically compiled into assemblies, an fsscript file is designed to be executed as a script. This means it can be run directly by the F# Interactive (FSI) tool without the need for a formal build process or project compilation. These files are widely used for rapid prototyping, data exploration, mathematical modeling, and automating tasks within the .NET ecosystem. Because they are interpreted at runtime, they allow developers to test snippets of code, perform data analysis, or write lightweight utilities quickly. The syntax within an fsscript file supports the full range of F# features, including type inference, pattern matching, and asynchronous workflows, making it a powerful tool for developers who need to iterate rapidly or perform ad-hoc scripting tasks in a strongly-typed environment.