LINQPad is a lightweight, interactive development utility for .NET — that lets developers write, run, and test code snippets and database queries without needing a full IDE. It supports C#, F#, VB.NET, and LINQ across multiple data sources (SQL Server, SQLite, Oracle, MySQL, Azure, etc.), provides rich real-time output formatting and debugging, and serves as a flexible code scratchpad and prototyping environment outside of Visual Studio. The Standard Edition remains free with no expiry, while optional paid features add advanced tooling and productivity enhancements.