Each year, I send out a Christmas card that I design on Scribus (featuring my comic strip or one of my comic panels). The back of the card also mentions that the card was desgined using Scribus on a Linux desktop.
Anyhow, in the past, I've wrestled with LibreOffice/OpenOffice and it's database function to get mailing labels printed. And, as much as I like using LibreOffice, I have to admit that the database side of things can be a bit clunky. In defense, though, i don't use it all the time, just once or twice a year. So, perhaps if I used it every day, familiarity would lead to ease of use.
Luckily, gLabels has a wonderful merge function! Just drop your tags in place in a label template, then get your database and print! Could not be easier. I just ran a hundred mailing labels here at the office via my notebook to a wireless laser print.
Now, all I have to do is sign, stuff, seal, and stick (on a label). Merry Christmas!