Future (desktop) operating systems — a collection of inspirations

• Artifacts, which is interesting for its document-focused design, the way it implements transclusion ("Links with context"), and a horizontal arrangement of documents as a way to organize workflows.
• Mercury OS, which has a striking visual design and showcases what a workflow and information-focused design for productivity could look like.
• Desktop Neo, which has a nice implementation of horizontally scrolling panes that connect apps together into workflows.
• Alexander Obenauer's Itemized OS, which reimagines personal computers to be more focused on information and open metadata to allow apps to extend each other around the information that matters, rather than organize into walled gardens.