From TDN

The Platform Layer: Why Torque Networking is cross-platform

At the very lowest level of the Torque Networking implementation is the platform layer. While a large majority of developers will never need to modify any code within the platform layer, it is important to understand what it does for you, since each platform that Torque is available for may handle networked traffic differently.

The Platform layer isolates the core functionality of networking from the operating system specific requirements of each target platform, so project developers can use a standard API without regard to the intended target platform. At compile time (based on your Makefile/Project specific configuration), the appropriate platform specific implementations are included in the executable, linking the developer's code to the appropriate implementation of the underlying Socket and Address classes. The platform layer also provides additional functionality that is OS-specific, but not critical to understanding the networking model, such as accessing system time, as well as wrappers for all of the standard C/C++ library functionality implemented for each target platform.