There are many approaches to this. Four of the more common for the background process are:

• A web server (like HTTP::Server::Simple)
• An irc bot which connects to an irc server to receive the commands (Bot::BasicBot
• A shared directory which the background process polls, or a named pipe/mailslot to which commands are written
• A database table into which new jobs are written

Depending on your needs and capabilities, any of these might be suitable or unsuitable. For example the webserver requires very little infrastructure and has lots of client tools and infrastructure available. The irc client requires more infrastructure, but allows easy restart/addition of both servers and clients as long as the irc server itself remains up. It provides no recovery/queueing of commands if no server can handle them. The filesystem approach can store things indefinitely but does usually have interesting problems when working over the network. Using a database requires the appropriate database and its drivers.

Other solutions are SMTP ("email"), a protocol which has very robust and established retry and failure mechanisms and scales very well.