Debunking error (OS 10054) core_output_filter: writing data to the network

One of our customers has Apache logs (Xampp-based) full of this line:
[Tue Mar 02 16:21:41 2010] [info] [client] (OS 10054)Une connexion existante a dû être fermée par l'hôte distant.  : core_output_filter: writing data to the network
Sometimes (OS10053) is used as a variant, but the Apache error seems to be the same (core_output_filter: writing data to the network) Apparently, the error is widespread and only occurs on Windows operating system (that's where OS10054 error code comes from) and a few useful references for this are:
  • (recommending to set EnableSendfile Apache's directive to Off)
  • (explaining the OS error is when a socket connection is not closed properly)
  • the problem does not seem to come from the programming language nor the application itself, as you can guess through
The same application running on a Linux box does not generate any core_output_filter error.