'Asio' is a cross-platform C++ library for network and low-level I/O programming that provides developers with a consistent asynchronous model using a modern C++ approach. 'Asio' is also included in Boost but requires linking when used with Boost. Standalone it can be used header-only provided a recent-enough compiler. 'Asio' is written and maintained by Christopher M. Kohlhoff. 'Asio' is released under the 'Boost Software License', Version 1.0.