I have worked in the printing industry for 4 years, dealing with many kinds of barcode generators and barcode readers. As to choose a particular barcode system, it all depends. The barcode we normally use is Barcode 128. There are perl modules on CPAN for generating it. Have a look at the Barcode::Code128 and GD::Barcode modules on CPAN. Your client obviously need to buy a barcode scanner. That comes with or without device drivers depending on the hardware. Install the barcode reader by connecting keyboard to the scanner, and then connect the scanner to the keyboard port. Now you scan the code, and it simulates key strokes. There is nothing much to it, really. You can read it with <STDIN>.