Marble

Marble is an online Markdown editor and collaborative workspace. Users can write Markdown with inline preview, tables, code blocks, LaTeX math and Mermaid diagrams.

Notes can be saved, organised and shared. A shared link lets others edit the same note together in real time, and joining does not require an account.

Notes stay in plain Markdown. Users can download them or save them as PDF, and they can connect AI tools such as Claude and ChatGPT to their notes.