Author here. The library itself (stackless_coroutine.hpp) has no dependencies other than C++14, and you can easily use it in any C++14 project with any async library.
For writing an interesting example, I wanted to do an example of how the library can simplify async network code. A widely used async C++ library is Boost.Asio, so that is what I used for the example.
TLDR: The library itself has no dependency on Boost. Boost.Asio was just used for the example.
I am planning on overhauling the example to use that latest version of Asio standalone that is tracking the C++ Networking TS. That way it will be a simple matter of people changing asio to std::experimental::net on a compiler that implements the Networking TS.