When preparing a tutorial for netxlite, I figured it is easier to tell people "hey, this is the package you should use for all low-level networking stuff" rather than introducing people to a set of packages working together where some piece of functionality is here and some other piece is there. Part of https://github.com/ooni/probe/issues/1591
Package github.com/ooni/probe-engine/legacy
This package contains legacy code that we will soon remove. When this folder is empty, it means there's no large, incremental refactoring in progress.