In the .Net space log4net is horrifically outdated and there's zero reason to use it today. Logging for modern .Net apps and libraries should be built on the Microsoft.Extensions.Logging abstractions which provide the type of features covered in TFA. They also provide a clear separation between generating log events in code and determining where & how logs are stored. For basic needs you can use simple log writers that tie in directly with MEL, or for advanced needs link MEL with Serilog so that you can use its sinks and log processing pipeline.