NQuery

NQuery is a relational query engine written in C#. It allows you to execute a SELECTquery against .NET objects. It can use arrays, data sets, data tablesor any other custom table binding. NQuery is completely extensible sothat you can add custom functions, aggregates, constants and parameters.

In addition to the query engine itself this project also contains an integration assembly with Actipro's SyntaxEditor so that you can author queries very easily. This includes code completion, parameter info and syntax highlighting.

Go to http://www.codeplex.com/NQuery

See also these related projects.