The folders in the "themes" folder are third party themes that are not hosted by the original theme developer anymore. Place the folder and its contents into your installation "themes" folder.
These themes are also listed on our site's themes section: http://www.zenphoto.org/theme/
Please remember that these scripts are provided for your use and education but are not supported by the Zenphoto team. This is true even if a team member originally created them.
They may not work correctly with current Zenphoto versions as they are not actively maintained. Although they may occasionally be updated for the current Zenphoto release.
We of course welcome any contribution or even taking over a certain theme: http://www.zenphoto.org/news/general-contributor-guidelines#providing-themes-and-plugins