LINQPad

LINQPad is an interactive environment for writing and executing C#, F#, and VB code snippets, full programs, and database queries. It lets developers prototype logic, test expressions, and run scripts without creating separate Visual Studio projects, and supports referencing custom assemblies and NuGet packages. The tool includes a REPL‑style workflow with autocompletion, debugging, and a rich output viewer called Dump that formats results for easy inspection.

For database work, LINQPad can connect to SQL Server, Azure SQL, SQLite, PostgreSQL, Oracle, and MySQL, allowing queries in LINQ or raw SQL with optional autocompletion. It automatically generates navigation properties from foreign‑key relationships, enabling intuitive traversal of related rows, and caches intermediate results via Util.Cache to avoid recomputation during iterative development.

LINQPad also integrates with popular .NET libraries such as BenchmarkDotNet, xUnit, Rx, MSAL, and Excel, and can be invoked from the command line or used to script automation tasks. The standard edition is free, lightweight, and runs on Windows and macOS.