The SketchPad application was designed to be a simple drawing editor that allows you to create elementary geometric shapes like lines and circles, and model them as entities using either the Entity Framework or LINQ to SQL.
Think of it as a ‘Notepad for Shapes’–you can create, read, and delete shapes, and use the built-in spatial index to search for entities by attribute value. A command-line argument allows you to switch between the Entity Framework and LINQ to SQL runtime for the model.