Manuskript might be a bit more popular than Sutori. We know about 1 link to it since March 2021 and only 1 link to Sutori. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
My first startup is Sutori (sutori.com), where we developed a presentation tool specifically for education. We sell to schools across the world. Source: over 2 years ago
Looks like you want something that integrates well with your workflow. The closest to your description seems to be Manuskript although I haven't used it. But your requirement of "keeping notes and frameworks and linking back and forth" should be possible by stitching together existing Linux tools using a syntax like markdown or asciidoc so that you can use any text editor to write your story and use external tools... Source: over 2 years ago
Timeline - Timeline is a cross-platform application for displaying and navigating events on a timeline.
Scrivener - Scrivener is a content-generation tool for composing and structuring documents.
Aeon Timeline - "The timeline tool for creative thinking. Capture, create and explore ideas."
yWriter - Free writing software designed by the author of the Hal Spacejock and Hal Junior series. yWriter6 helps you write a book by organising chapters, scenes, characters and locations in an easy-to-use interface.
Preceden - Preceden makes it easy to build simple, powerful timelines
StoryMill - Developers and publishers of Mac, Win, and iOS productivity, home and office and writing software such as MacGourmet, Paperless and many more. Based in MN.