Entity framework PostgreSQL
Entity framework also works with Npgsql - .Net Data Provider for Postgresql.A tutorial on how to set it up can be found here:http://www.npgsql.org/ef6/index.html
Devart has a product that gives entity framework support for PostgreSQL. See:
http://www.devart.com/dotconnect/postgresql/
There is a provider for mono for postgreSQL. See: