There are something like a squillion and one different Avery® and Avery-compatible address labels you can buy, and with the open source LibreOffice productivity suite you can easily create your own custom fancy return address labels.

Sometimes alphanumeric text simply won’t cut it, and you need a bar code — mailing labels, security badges, inventory tracking, perhaps even URL-encoding for mobile phones. With KBarcode, you can use a simple desktop application to generate several dozen different barcode types

A 2 part article: In the world of label creation software for Linux, gLabels is the long-standing market leader. It offers a convenient graphical interface in which you can design labels with the same tools you are used to finding in image editing software, but it also supports business-friendly advanced features like “mail merge” and barcode generation

Designing labels & cards is a straightforward process with Scribus: you import the proper template, lay out one label the way you want it, then duplicate your creation to fill the rest of the slots on the template. To get the best results, however, you will need to make use of some specific features: layers, text styles, and more.

Many users are content with the label and mail merge features in OpenOffice.org Writer, Abiword or KOffice for basic jobs. What if you want a smaller, dedicated program for elaborate formatting or graphics. In these cases, you should consider turning to gLabels.