HN user
Looks great! The two-cursor feature would also be extremely useful when two mice are connected to one computer. We do pair programming at work and I could see a tool that allows two people sitting at one machine to each have their own cursor totally transforming the way we work. Is this a feature you plan on developing?
I like this technique, and I think it would be appropriate to extend it other hierarchical types of data besides just text. For example, a product page might show a list of reviews, with each shown as x/5 stars, and zooming in on the reviews would show the review text. Same with product info - zoomed out = overview, zoomed in: more details appear. This would require zooming in on a specific section of a page though, not just making the entire page bigger. Imagine browsing an online store or search results by zooming in/out using a touch interface, rather than clicking on links to details/reviews/photos