At my last job I had built a system where users could enter text into a quill textbox (and style it), and then save it into a database in their delta format. Later, a different team member would pull that into an InDesign plugin where we could easily read what styles had been applied to the text in quill, and style that using the styling in InDesign. This was used when the front desk person would enter in a legal notice for a newspaper, and the production team would be the ones who would get that into InDesign for printing. The quill delta format that it uses made this process so much easier than if we were to have been given HTML like most other editors output / save. Glad to see this is still around, its been a few years since I had heard / used quill.