Npgsql is an open source ADO.NET Data Provider for PostgreSQL, it allows programs written in C#, VisualBasic, F# to access the PostgreSQL database server. It is implemented in 100% C# code, is free and is open source. An Entity Framework Core provider is also available and exposes some features unique to the PostgreSQL database to EF Core users. Finally, a legacy Entity Framework 6.x (non-Core) provider is also available but is no longer being actively maintained.
NLog is a logging platform for .NET with rich log routing and management capabilities. It uses familar logger pattern known from log4xxx. Advanced routing options include buffering, asynchronous logging, load balancing, failover, and more.