Differences between 1.3.9 and 1.5.1

Can someone please point me to a document that lists the differences/changes between 1.3.9 and 1.5.1?

I have two clients with 1.3.9 installations (one a and one h) and they're asking if they should upgrade. I'd like to be able to give them some specifics.

Thanks,

John

Look in the /docs folder of the 1.5.1 installation package.

Here are the release announcements:
http://www.zen-cart.com/showthread.php?190424-v1-5-0
http://www.zen-cart.com/showthread.php?200259-Zen-Cart-v1-5-1

Yes, the /docs/ folder contains the same info.

Also remember that PHP keeps releasing new versions, and so does Zen Cart. You can't use an obsolete version of Zen Cart on a new version of PHP.

Thanks Steve and Dr. Byte!

So I read the long list of changes (some of which I guess must be ZC insider knowledge like the one that referred to chickens, eggs and garbage).

Here's my question - -if my clients are basically happy with their installs and they are not experiencing of the bugs that are fixed in the upgrade, should they upgrade? I did notice a few changes that look like security issues -- but I'm not sure how significant they are.

John

1.3.9h is secure (I would at least upgrade the 1.3.9a site to h), but if your clients haven't installed a lot of mods that modify non-overridable files or mods for which 1.5.1 versions aren't available, I would upgrade both to 1.5.1, if for no other reason than the possibility that an upgrade from 1.3 to 1.6 might be even more difficult. I think doing upgrades to every new version is a good habit to get in to.

Thanks Steve -- that's just the kind of advice I was looking for.