Dynamic .NET SQL queries
This project started as an experiment that allowed me to write dynamic SQL-like inline queries so I could explore the nature of my collection of MP3 files. This original project is on CodeProject: http://www.codeproject.com/Articles/28163/SqlLinq-Taking-LINQ-to-SQL-in-the-Other-Direction.
That original code was refined to being a basic implementation of SQL select statements. That code was also published and described on CodeProject: http://www.codeproject.com/Articles/43678/Dynamically-evaluated-SQL-LINQ-queries
It isn't a replacement for Linq but it can come in handy when the data model being queried or the exact structure of one's query results aren't known at compile time.