No. It has a file structure and PDFs with layers. That is it.
Discussion
Ugh, PDFs.
Yes.
Without using PDF they'd have to convert handwritten text to machine encoding, which isn't always accurate.
Yes. I have to begrudgingly admit that PDF is the best available solution for mixing text and vector drawings. They save a path and a tool. The path itself, I think, encodes angle and pressure.
Couldn't you just build your own and include a dedicated browser that only runs Alexandria?
Yes. There are more open alternatives. Like the Supernote that are android based that you could put some effort into. I really don't like embedded browsers though. The idealist in me recoils from the waste and bloat.