 <p>The purest way I can think of to do this is with IPC. Python has very good support for IPC between two processes when one process spawns another, but not in your scenario. There are python modules for ipc such as <code>sysv_ipc</code> and <code>posix_ipc</code>. But if you are going to have your main application built in tornado, why not just have it listen on a <code>zeromq</code> socket for published messages.</p> <p>Here is a link with more information. You want the Publisher-Subscriber model.</p> <p><a href="http://zeromq.github.io/pyzmq/eventloop.html#tornado-ioloop" rel="nofollow">http://zeromq.github.io/pyzmq/eventloop.html#tornado-ioloop</a></p> <p>Your cron job will start and publish messages a to <code>zeromq</code> socket. Your already running application will receive them as subscriber.</p>