Dapper describes itself as "a simple object mapper for .Net". It is one of the earilest "Micro-ORMs" and in keeping with that style, it is exposed as a set of extension methods over ADO.NET's
Dapper's primary purpose is to handle mapping objects to database parameters and result sets to objects. It does not provide SQL generation.
Dapper supports any database that offers an ADO.NET provider.
ADO.NET requires the writing of SQL, which is often database specific.
Unless otherwise indicated, all examples of SQL are for SQL Server.
Dapper uess the same setup as ADO.NET. No additional setup is required.
Issues should be logged in the StackExchange/Dapper repository.
Dapper is offered under the Apache License version 2.