The simpler media website CMS
I recently downloaded ZenPhoto v1.5 from www.zenphoto.org. Then spent hours troubleshooting a non-loading setup page.
Browsing forum.zenphoto.org provides clues to why users get blank pages when accessing the setup page of a new installation:
In short, the download package on the main website has a bug that renders ZenPhoto dead-on-arrival.
Since I don't know how the ZenPhoto community is organized, I can't recommend any specific action,
and can only implore any active members to take action and replace the downloadable package with the working (master) from Github.