Folia is supposed to blow "the socks off of the linear word processors we’ve all been stuck using. It’s inspired by years of work observing how we communicate, learn, and record ideas (and of course our experience with iAnnotate)."
It's supposed to be more than "just a word processor with web-like links" because "connections in Folia are more powerful than the links we use on the web. Links on the web are just hollow connections between two pages, they provide limited information about why the link exists or which specific parts of a linked document are relevant. Frankly, I think it’s this limitation of HTML-style links that has prevented linking from becoming a more ubiquitous part of creating, writing, etc."
I was excited, I downloaded the application, and I opened it ... only to be greeted by a screen with "username" and "password" fields. It turns out that "in order to use Folia and view folias shared with you, you will need to be registered. ... The app is offered free of charge for a limited time but subscription pricing will take effect in future versions." This is revealed in the Frequently Asked Questions page.
I did not register and deleted the application. Someone else might not mind the proprietary format and lack of control over their own data as much as I do. Though I am intrigued by their claims about linking, I am not going to waste any more time on this application.
The application is available for free in Apple's Application Store. I should have read the customer reviews before downloading, as they mirror my main concern. I would also have found out that you cannot even print from the application.