Azos is based on .Net Standard 2, having all cli tools targeting both .NET FX 4.7.1+ and .NET Core 2+. Azos does not support fx < 4.7.1 (though possible).
NFXv3* (this repository) will continue to target .NET 4.5/Mono and may get some support for major bug fixes however all new feature development is going to happen in the NEW REPO for Azos.
Server UNISTACK (unified full software stack, no 3rd paty libs) framework.