HackMD

HackMD is a web-based workspace built for writing and sharing documents using Markdown. Its core function is to let multiple people edit the same Markdown note at the same time, seeing each other's changes live. You can use it for everything from simple personal to-do lists to complex team documentation, presentations, and research notes. It's designed to be a central hub for knowledge that needs to be created and accessed by a group.

It works in your browser and focuses on the simplicity of Markdown while adding powerful collaboration features. You can organize related notes into 'Books' for better structure, use pre-made templates to speed up common tasks like writing meeting minutes, and even draw UML diagrams and flowcharts using text-based syntax. A standout feature is its direct integration with GitHub, allowing you to push notes to a repository or pull changes from it, keeping your docs and code in sync.

This tool is most useful for teams that need to write and maintain documentation together, such as software developers, open-source project contributors, research groups, and educators. It removes the friction of sharing draft documents and version confusion. Real-world use includes an engineering team drafting an API spec together, a study group co-authoring shared lecture notes, or a community project maintaining public documentation that anyone can suggest edits to.