I am trying to architect a very specific CMS solution and so far I've come up short when it comes to the more popular options.
Notably I need a CMS that
- is open-source,
- is extensible (plugins/themes),
- is hopefully available as a SAAS solution,
- has a native API or can be configured to have an API via plugin/whatever,
- can be configured to offer an arbitrarily modular experience when authoring content (arbitrary text/image/embed/etc. blocks that can be positioned arbitrarily relative to one another),
- and have some kind of mechanism (plugin or natively) for syncing specific content between CMS installs (this is the condition that's causing me the most trouble).
I feel like I've explored most options, but I'm not terribly confident I've explored them all, any suggestions would be greatly appreciated!
(There are notable solutions for these conditions in Drupal 7, but if it's not Drupal 8 it's not an option. Waiting for these features/modules to be feature complete in Drupal 8 is not an option either.)