Composer vs HackMD

Composer is a web-based, real-time Markdown editor where people and AI agents work on shared documents. Agents connect through MCP and join documents as collaborators, with permission to read and write shared content. Changes synchronize across teammates, devices, and sessions. Composer uses plain Markdown, keeping files readable in other editors, and supports Markdown export. The listed publishing workflow is none. Free users receive unlimited public documents and collaborators, plus up to seven private documents, three collaborators per private document, and a 10 MB upload limit. Pro removes the private-document and collaborator limits and adds early access to new features. Pro Annual costs $5.99 a month billed annually at $71.88 a year; Pro Monthly costs $7.99 a month billed monthly. Users can cancel anytime, with paid access continuing through the period. Stripe handles checkout.

HackMD has no write-up on Specifiction yet; its figures are above.