Great question. We'd look at Obsidian as a reference.
We think there are a lot of value added services that can happen when you need servers, but they should be user aligned & optional (Mobile app, sync, publishing, backups, remote jobs, collab).
We want Surf's client to be independent & open, but offer some of these on top -- for people who want them!
Surf is built entirely on editable WYSIWYG documents, NotebookLM's main AI is built on chat. Surf is built to be a bit more open, NotebookLM was a bit locked down for our taste.
An example I'd highlight is taking notes against a PDF.
NotebookLM will convert the PDF to simple text, and the chat responses are read only. NotebookLM also has a lot of strict walls between chat, artifacts & sources. You have to "save" responses as (read only) notes, and move notes to sources.
With Surf you can generate notes that deep link to specific pages in the PDF, and Surf will open those pages in the original PDF. You can remove the fluff you don't want in your notes. The intention is to be a little more open -- all notes are sources from the get go, you don't have to save or migrate anything.
The big difference UX wise between chatbots and Surf is that Surf is built entirely on editable documents that you can mold / craft into an output (vs chat).
We actually had a chatbot, but our explorations showed that notes were a more effective in many cases!
An example of local data is that "Applets" made in Surf can be opened / updated from your local code editor, they're just HTML files.
Yes great point. Photos are intended as a very important subset of media.
Not (yet) super usable, but for photos we have local OCR running, with Surf creating additional metadata (e.g. the link from where the photo was downloaded).
Can imagine some use cases -- off the top of my head, suggesting the right photos to embed in a note in response to a user query.
We took inspiration from analog notebooks as a tool for thought, but wanted something for multi-media. We also see NotebookLM as the closest mainstream product to Surf.
Related -- some people who have seen Surf's Applets feature have also called Surf "Jupyter for normies".
Basically you can supply input context and a runnable file will generate & run in your document. Useful for creating interactive charts or small applets.
Our philosophy is that if you want to update it, you should be able use your local code editor, not be stuck in Surf!
One big distinction: we aren't trying to automate people's browsing / clicking, but augment people's thinking.
This creates a different feature set / model: tabs feeding into a document vs a chat going off and automating activity in tabs.