GNU Barcode X is a Mac OS X GUI frontend for the GNU barcode program. The program generates 1-D barcodes, most notably EAN and UPC barcodes. The program was written in order to simplify the barcode creation process for some people. Both the original GNU barcode (which is included in the DMG) and this GUI frontend is licensed through the GPL. You can download it here (includes both the binaries and the source code): GNU Barcode X.dmg.