Along the same lines as Gallery check out http://www.zenphoto.org/
It's made to be simpler than Gallery.  I like it better than Gallery2
but I haven't used the latest version of Gallery3 which I think was a
rewrite so it's probably pretty different than Gallery2.  Both are open
source, written in PHP, and are pretty customizable if you have the
time.

Quoting Genny Engel <[log in to unmask]>:

> At one point I was trying out the Gallery module for Drupal.  The
> module is for integrating the otherwise standalone Gallery.
>
> http://galleryproject.org/
>
> I ended up going with something else for Drupal, but in a standalone
> situation, I'd definitely give Gallery another look.
>
> Genny Engel
> Sonoma County Library
> [log in to unmask]
> 707 545-0831 x1581
> www.sonomalibrary.org
>
> -----Original Message-----
> From: Code for Libraries [mailto:[log in to unmask]] On Behalf
> Of Ken Irwin
> Sent: Thursday, November 07, 2013 12:44 PM
> To: [log in to unmask]
> Subject: [CODE4LIB] image gallery management software recommendations
>
> Hi all,
>
> I'm working on a project for which we're looking for some image
> gallery management software (ie, upload, organize, tag, etc.) that's
> a standalone piece of software: ie, not part of a larger CMS like
> WordPress, Drupal, ContentDM, etc.
>
> We'd of course like something that is simple, awesome, and free. (We
> might settle for two of the three...) The only absolute requirement
> is that it needs to run on a Linux/Apache server. PHP/MySQL would be
> preferred, and something with a responsive front-end would also be
> nice.
>
> The world appears to be teeming with such things of various quality;
> I thought I'd ask you all for recommendations rather than just try to
> wade through the masses of junk.
>
> Any ideas?
> Thanks
> Ken
>