LINQPad - A scratchpad for C#, F# and VB code including Linq queries.
SQL Developer - Oracle SQL Developer is a free, development environment that simplifies the management of Oracle Database in both traditional and Cloud deployments.
Linqer - Linqer is a SQL to LINQ converter tool.
Toad Edge - Windows GUI for MySQL. SQL Syntax Check. Freeware (Basic Features) & Payware (Extended Features).
Snippet Compiler - Authors description: "Snippet Compiler compiles snippets."
DbVisualizer - DbVisualizer is the universal database tool for developers, DBAs and analysts.