LINQPad - A scratchpad for C#, F# and VB code including Linq queries.

Quiver - Quiver is a notebook built for programmers.

LINQ Insight - Execute LINQ Queries directly from Visual Studio without building the application. Verify your LINQ queries in a single click and view data with LINQ Insight!

Code Bank - Code Bank is a code snippet manager with support for a local database as well as a shared database.

Dot Net Editor - An VB/C# text editor with the ability to run code and code snippets.

GitHub Gist - Gist is a simple way to share snippets and pastes with others.