Periplus generates courses as connected markdown documents, tailored to your level. It asks a few questions upfront, builds a syllabus, and each concept links to related ones. Click a term you don't understand and it opens a new document side-by-side.
Heavy inspiration from Obsidian - the graph view is similar, and there's an Obsidian export if you want to keep your notes locally.
It also generates quizzes and flashcards from any document, which helps with the forgetting problem I always have with passive reading.
Stack: React, Node/Express, Postgres with pgvector, Sonnet 4.5 for generations. Graph uses D3 with a WASM-optimized many-body I made [1].
Still plenty to iron out! Would love feedback on course quality, I've mostly tested technical topics.