This page embeds the curl executable (command line interface to libcurl) built with NaCl. Because it needs to use the chrome socket API, chrome must be lunched with --allow-nacl-socket-api=localhost (or whatever host you are loading this page from).
Arguments can be passed to curl using the following form, or by adding "arg1", "arg2", etc to the URL query paramaters.The terminal window below shows the output of curl.