EF Core
There is still no official solution from ProgressSw but I can recommend the provider from Alex Wiese (see Answer below): EntityFrameworkCore.OpenEdge
EF 6 (.Net Framework)
Because ODBC is the only supported Interface for .net Clients you can't use OpenEdge DB with Entity Framework directly (Why doesn't Entity Framework support ODBC?).
But there is a commercial ADO.NET Driver for OpenEdge from OpenLink and an unofficial NHibernate Dialect.