Given description is valid for modern Linux and may be slightly different on other systems.

I agree. Depending on whatever crappy windows version one uses, blocking sockets may not block or non-blocking sockets may block. And there's a difference between blocking while communicating and blocking while waiting for a new connection.

For me, it was always a bit confusing when switching between Windows and Linux - or to be more precise developing basic TCP connections anywhere. I "fixed" this PEBCAC problem by switching to HTTP whenever possible. In my case, this usually means HTTP::Server::Simple::CGI or Maplat on the server and something like WWW::Mechanize::GZip on the client.

Of course, this is only my small, personal development universe, yours may have different requirements and bugs or a even better developer altogether...