Upgrading Zen 7.x-3.x to 7.x-5.x

Do you need to upgrade?

Nope. If you have a working sub-theme using Zen 7.x-3.1, you do not need to upgrade to Zen 7.x-5.x.

The primary purpose of Zen is to aid theme development. If you have finished development and have a working sub-theme, don't worry. Zen 7.x-3.x will remain supported for a long time; there's no need to upgrade just so you have “the latest and greatest.”

Why would you want to upgrade?

• You have a contributed theme on Drupal.org and you want it to support Zen 7.x-5.x
• You want your site to be responsive. There's no magic button you can press to make your site responsive. It's going to take a significant redesign of your site. Zen 5 will help with that process if you want to undertake it. But it won't do the work for you either.

It's probably easiest to create a new fresh Zen 7.x-5.x sub-theme and then copy over pieces one-by-one from your old 7.x-3.x sub-theme.

Users with alternative methods are encouraged to share their process here. :-)